XML 47 R26.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Derivatives and Fair Value of Financial Instruments (Details) (USD $) | 3 Months Ended |
--- | --- | ---
Apr. 04, 2015 | Dec. 31, 2014
Derivatives and Fair Value of Financial Instruments |  |
Transfers that occurred into or out of level 1 | $ 0 seb_FairValueMeasurementTransfersIntoOrOutOfLevel1 |
Transfers that occurred into or out of level 2 | 0 seb_FairValueMeasurementTransfersIntoOrOutOfLevel2 |
Transfers that occurred into or out of level 3 | 0 seb_FairValueMeasurementTransfersIntoOrOutOfLevel3 |
Commodities |  |
Assets: |  |
Margin account | 21,752,000 us-gaap_MarginDepositAssets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember | 4,314,000 us-gaap_MarginDepositAssets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember
Money market funds |  |
Assets: |  |
Available-for-sale securities | 236,974,000 us-gaap_AvailableForSaleSecurities / invest_InvestmentAxis = us-gaap_MoneyMarketFundsMember | 142,432,000 us-gaap_AvailableForSaleSecurities / invest_InvestmentAxis = us-gaap_MoneyMarketFundsMember
Corporate bonds |  |
Assets: |  |
Available-for-sale securities | 11,757,000 us-gaap_AvailableForSaleSecurities / invest_InvestmentAxis = us-gaap_CorporateBondSecuritiesMember | 11,015,000 us-gaap_AvailableForSaleSecurities / invest_InvestmentAxis = us-gaap_CorporateBondSecuritiesMember
U.S. Government agency securities |  |
Assets: |  |
Available-for-sale securities | 9,354,000 us-gaap_AvailableForSaleSecurities / invest_InvestmentAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember | 9,666,000 us-gaap_AvailableForSaleSecurities / invest_InvestmentAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Asset backed debt securities |  |
Assets: |  |
Available-for-sale securities | 2,554,000 us-gaap_AvailableForSaleSecurities / invest_InvestmentAxis = us-gaap_AssetBackedSecuritiesMember | 2,291,000 us-gaap_AvailableForSaleSecurities / invest_InvestmentAxis = us-gaap_AssetBackedSecuritiesMember
U.S. Treasury securities |  |
Assets: |  |
Available-for-sale securities | 1,996,000 us-gaap_AvailableForSaleSecurities / invest_InvestmentAxis = us-gaap_USTreasurySecuritiesMember | 522,000 us-gaap_AvailableForSaleSecurities / invest_InvestmentAxis = us-gaap_USTreasurySecuritiesMember
Collateralized mortgage obligations |  |
Assets: |  |
Available-for-sale securities | 816,000 us-gaap_AvailableForSaleSecurities / invest_InvestmentAxis = us-gaap_CollateralizedMortgageObligationsMember | 1,170,000 us-gaap_AvailableForSaleSecurities / invest_InvestmentAxis = us-gaap_CollateralizedMortgageObligationsMember
High yield debt securities |  |
Assets: |  |
Trading securities | 175,390,000 us-gaap_TradingSecurities / invest_InvestmentAxis = seb_HighYieldTradingDebtSecuritiesMember | 181,483,000 us-gaap_TradingSecurities / invest_InvestmentAxis = seb_HighYieldTradingDebtSecuritiesMember
Equity mutual fund |  |
Assets: |  |
Trading securities | 86,268,000 us-gaap_TradingSecurities / invest_InvestmentAxis = seb_EquityMutualFundsMember | 82,542,000 us-gaap_TradingSecurities / invest_InvestmentAxis = seb_EquityMutualFundsMember
Domestic equity ETF |  |
Assets: |  |
Trading securities | 61,806,000 us-gaap_TradingSecurities / invest_InvestmentAxis = us-gaap_ExchangeTradedFundsMember | 32,651,000 us-gaap_TradingSecurities / invest_InvestmentAxis = us-gaap_ExchangeTradedFundsMember
Money market funds held in trading accounts |  |
Assets: |  |
Trading securities | 6,362,000 us-gaap_TradingSecurities / invest_InvestmentAxis = seb_MoneyMarketFundsHeldInTradingAccountsMember | 21,401,000 us-gaap_TradingSecurities / invest_InvestmentAxis = seb_MoneyMarketFundsHeldInTradingAccountsMember
Emerging markets trading debt mutual fund |  |
Assets: |  |
Trading securities | 2,550,000 us-gaap_TradingSecurities / invest_InvestmentAxis = seb_EmergingMarketsTradingDebtMutualFundsMember | 2,614,000 us-gaap_TradingSecurities / invest_InvestmentAxis = seb_EmergingMarketsTradingDebtMutualFundsMember
Recurring basis | Fair Value |  |
Assets: |  |
Total Assets | 652,559,000 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 546,012,000 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Liabilities: |  |
Liabilities | 19,402,000 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 9,901,000 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Recurring basis | Fair Value | Commodities |  |
Assets: |  |
Derivatives | 4,147,000 us-gaap_DerivativeAssets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 6,136,000 us-gaap_DerivativeAssets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Margin account | 21,752,000 us-gaap_MarginDepositAssets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 4,314,000 us-gaap_MarginDepositAssets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Liabilities: |  |
Derivatives | 9,722,000 us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 1,779,000 us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Recurring basis | Fair Value | Interest rate swaps |  |
Liabilities: |  |
Derivatives | 9,256,000 us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 7,715,000 us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Recurring basis | Fair Value | Foreign currencies |  |
Assets: |  |
Derivatives | 1,039,000 us-gaap_DerivativeAssets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_ForeignExchangeContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 1,675,000 us-gaap_DerivativeAssets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_ForeignExchangeContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Liabilities: |  |
Derivatives | 424,000 us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_ForeignExchangeContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 407,000 us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_ForeignExchangeContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Recurring basis | Fair Value | Other current assets | Commodities |  |
Assets: |  |
Derivative assets and liabilities, net basis | 16,612,000 seb_NetFairValueOfDerivativeAssetsNetOfDerivativeLiabilitiesAndNetOfMarginDeposit / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember | 9,267,000 seb_NetFairValueOfDerivativeAssetsNetOfDerivativeLiabilitiesAndNetOfMarginDeposit / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember
Recurring basis | Fair Value | Other current liabilities | Commodities |  |
Liabilities: |  |
Derivatives | 435,000 us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentLiabilitiesMember | 596,000 us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentLiabilitiesMember
Recurring basis | Fair Value | Money market funds |  |
Assets: |  |
Available-for-sale securities | 236,974,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_MoneyMarketFundsMember |
Recurring basis | Fair Value | Money market funds | Short-term investments. |  |
Assets: |  |
Available-for-sale securities |  | 142,432,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_MoneyMarketFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Fair Value | Corporate bonds |  |
Assets: |  |
Available-for-sale securities | 11,757,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_CorporateBondSecuritiesMember |
Recurring basis | Fair Value | Corporate bonds | Short-term investments. |  |
Assets: |  |
Available-for-sale securities |  | 11,015,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_CorporateBondSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Fair Value | U.S. Government agency securities |  |
Assets: |  |
Available-for-sale securities | 9,354,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember |
Recurring basis | Fair Value | U.S. Government agency securities | Short-term investments. |  |
Assets: |  |
Available-for-sale securities |  | 9,666,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Fair Value | Asset backed debt securities |  |
Assets: |  |
Available-for-sale securities | 2,554,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_AssetBackedSecuritiesMember |
Recurring basis | Fair Value | Asset backed debt securities | Short-term investments. |  |
Assets: |  |
Available-for-sale securities |  | 2,291,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Fair Value | U.S. Treasury securities | Short-term investments. |  |
Assets: |  |
Available-for-sale securities | 1,996,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_USTreasurySecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember | 522,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_USTreasurySecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Fair Value | Collateralized mortgage obligations |  |
Assets: |  |
Available-for-sale securities | 816,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_CollateralizedMortgageObligationsMember |
Recurring basis | Fair Value | Collateralized mortgage obligations | Short-term investments. |  |
Assets: |  |
Available-for-sale securities |  | 1,170,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_CollateralizedMortgageObligationsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Fair Value | High yield debt securities | Short-term investments. |  |
Assets: |  |
Trading securities | 175,390,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_HighYieldTradingDebtSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember | 181,483,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_HighYieldTradingDebtSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Fair Value | Equity mutual fund | Short-term investments. |  |
Assets: |  |
Trading securities | 86,268,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_EquityMutualFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember | 82,542,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_EquityMutualFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Fair Value | Domestic equity ETF | Short-term investments. |  |
Assets: |  |
Trading securities | 61,806,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_ExchangeTradedFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember | 32,651,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_ExchangeTradedFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Fair Value | Money market funds held in trading accounts | Short-term investments. |  |
Assets: |  |
Trading securities | 6,362,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_MoneyMarketFundsHeldInTradingAccountsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember | 21,401,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_MoneyMarketFundsHeldInTradingAccountsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Fair Value | Emerging markets trading debt mutual fund | Short-term investments. |  |
Assets: |  |
Trading securities | 2,550,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_EmergingMarketsTradingDebtMutualFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember | 2,614,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_EmergingMarketsTradingDebtMutualFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Fair Value | Other trading investments | Short-term investments. |  |
Assets: |  |
Trading securities | 1,792,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_OtherDebtSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember | 2,779,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_OtherDebtSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Fair Value | Domestic equity securities | Other current assets |  |
Assets: |  |
Trading securities | 35,600,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_DomesticEquitySecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember | 33,857,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_DomesticEquitySecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember
Recurring basis | Fair Value | Foreign equity securities | Other current assets |  |
Assets: |  |
Trading securities | 6,780,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_ForeignEquitySecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember | 6,532,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_ForeignEquitySecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember
Recurring basis | Fair Value | Fixed income mutual funds | Other current assets |  |
Assets: |  |
Trading securities | 4,415,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_FixedIncomeFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember | 4,570,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_FixedIncomeFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember
Recurring basis | Fair Value | Other | Other current assets |  |
Assets: |  |
Trading securities | 2,959,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_OtherAggregatedInvestmentsMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember | 2,676,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_OtherAggregatedInvestmentsMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember
Recurring basis | Level 1 |  |
Assets: |  |
Total Assets | 447,413,000 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 335,140,000 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Liabilities: |  |
Liabilities | 9,722,000 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 1,779,000 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Recurring basis | Level 1 | Commodities |  |
Assets: |  |
Derivatives | 4,147,000 us-gaap_DerivativeAssets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 6,136,000 us-gaap_DerivativeAssets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Liabilities: |  |
Derivatives | 9,722,000 us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 1,779,000 us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Recurring basis | Level 1 | Money market funds |  |
Assets: |  |
Available-for-sale securities | 236,974,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_MoneyMarketFundsMember |
Recurring basis | Level 1 | Money market funds | Short-term investments. |  |
Assets: |  |
Available-for-sale securities |  | 142,432,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_MoneyMarketFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Level 1 | Equity mutual fund | Short-term investments. |  |
Assets: |  |
Trading securities | 86,268,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_EquityMutualFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember | 82,542,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_EquityMutualFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Level 1 | Domestic equity ETF | Short-term investments. |  |
Assets: |  |
Trading securities | 61,806,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_ExchangeTradedFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember | 32,651,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_ExchangeTradedFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Level 1 | Money market funds held in trading accounts | Short-term investments. |  |
Assets: |  |
Trading securities | 6,362,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_MoneyMarketFundsHeldInTradingAccountsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember | 21,401,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_MoneyMarketFundsHeldInTradingAccountsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Level 1 | Emerging markets trading debt mutual fund | Short-term investments. |  |
Assets: |  |
Trading securities | 2,550,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_EmergingMarketsTradingDebtMutualFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember | 2,614,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_EmergingMarketsTradingDebtMutualFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Level 1 | Domestic equity securities | Other current assets |  |
Assets: |  |
Trading securities | 35,600,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_DomesticEquitySecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember | 33,857,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_DomesticEquitySecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember
Recurring basis | Level 1 | Foreign equity securities | Other current assets |  |
Assets: |  |
Trading securities | 6,780,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_ForeignEquitySecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember | 6,532,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_ForeignEquitySecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember
Recurring basis | Level 1 | Fixed income mutual funds | Other current assets |  |
Assets: |  |
Trading securities | 4,415,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_FixedIncomeFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember | 4,570,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_FixedIncomeFundsMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember
Recurring basis | Level 1 | Other | Other current assets |  |
Assets: |  |
Trading securities | 2,511,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_OtherAggregatedInvestmentsMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember | 2,405,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_OtherAggregatedInvestmentsMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember
Recurring basis | Level 2 |  |
Assets: |  |
Total Assets | 205,146,000 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 210,872,000 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Liabilities: |  |
Liabilities | 9,680,000 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 8,122,000 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Recurring basis | Level 2 | Interest rate swaps |  |
Liabilities: |  |
Derivatives | 9,256,000 us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 7,715,000 us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateSwapMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Recurring basis | Level 2 | Foreign currencies |  |
Assets: |  |
Derivatives | 1,039,000 us-gaap_DerivativeAssets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_ForeignExchangeContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 1,675,000 us-gaap_DerivativeAssets / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_ForeignExchangeContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Liabilities: |  |
Derivatives | 424,000 us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_ForeignExchangeContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 407,000 us-gaap_DerivativeLiabilities / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_ForeignExchangeContractMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Recurring basis | Level 2 | Corporate bonds |  |
Assets: |  |
Available-for-sale securities | 11,757,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_CorporateBondSecuritiesMember |
Recurring basis | Level 2 | Corporate bonds | Short-term investments. |  |
Assets: |  |
Available-for-sale securities |  | 11,015,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_CorporateBondSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Level 2 | U.S. Government agency securities |  |
Assets: |  |
Available-for-sale securities | 9,354,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember |
Recurring basis | Level 2 | U.S. Government agency securities | Short-term investments. |  |
Assets: |  |
Available-for-sale securities |  | 9,666,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Level 2 | Asset backed debt securities |  |
Assets: |  |
Available-for-sale securities | 2,554,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_AssetBackedSecuritiesMember |
Recurring basis | Level 2 | Asset backed debt securities | Short-term investments. |  |
Assets: |  |
Available-for-sale securities |  | 2,291,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_AssetBackedSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Level 2 | U.S. Treasury securities | Short-term investments. |  |
Assets: |  |
Available-for-sale securities | 1,996,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_USTreasurySecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember | 522,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_USTreasurySecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Level 2 | Collateralized mortgage obligations |  |
Assets: |  |
Available-for-sale securities | 816,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_CollateralizedMortgageObligationsMember |
Recurring basis | Level 2 | Collateralized mortgage obligations | Short-term investments. |  |
Assets: |  |
Available-for-sale securities |  | 1,170,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_CollateralizedMortgageObligationsMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Level 2 | High yield debt securities | Short-term investments. |  |
Assets: |  |
Trading securities | 175,390,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_HighYieldTradingDebtSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember | 181,483,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = seb_HighYieldTradingDebtSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Level 2 | Other trading investments | Short-term investments. |  |
Assets: |  |
Trading securities | 1,792,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_OtherDebtSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember | 2,779,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_OtherDebtSecuritiesMember / us-gaap_InvestmentTypeAxis = us-gaap_ShortTermInvestmentsMember
Recurring basis | Level 2 | Other | Other current assets |  |
Assets: |  |
Trading securities | $ 448,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_OtherAggregatedInvestmentsMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember | $ 271,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / invest_InvestmentAxis = us-gaap_OtherAggregatedInvestmentsMember / us-gaap_InvestmentTypeAxis = us-gaap_OtherCurrentAssetsMember

X
- Details
Name: | seb_DerivativesAndFairValueOfFinancialInstrumentsDisclosureAbstract
Namespace Prefix: | seb_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the transfers into or out of level 1 fair value hierarchy that have taken place during the period. + References No definition available. + Details
Name: | seb_FairValueMeasurementTransfersIntoOrOutOfLevel1
Namespace Prefix: | seb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Represents the transfers into or out of level 2 fair value hierarchy that have taken place during the period. + References No definition available. + Details
Name: | seb_FairValueMeasurementTransfersIntoOrOutOfLevel2
Namespace Prefix: | seb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Represents the transfers into or out of level 3 fair value hierarchy that have taken place during the period. + References No definition available. + Details
Name: | seb_FairValueMeasurementTransfersIntoOrOutOfLevel3
Namespace Prefix: | seb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fair value as of the balance sheet date of derivative assets and derivative liabilities, presented on a net basis, and also net of related margin accounts. + References No definition available. + Details
Name: | seb_NetFairValueOfDerivativeAssetsNetOfDerivativeLiabilitiesAndNetOfMarginDeposit
Namespace Prefix: | seb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_AssetsFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 + Details
Name: | us-gaap_AvailableForSaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13433-108611 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13495-108611 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=34720828&loc=SL20225862-175312 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=36459792&loc=SL20226008-175313 + Details
Name: | us-gaap_DerivativeAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13433-108611 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13495-108611 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=34720828&loc=SL20225862-175312 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=36459792&loc=SL20226008-175313 + Details
Name: | us-gaap_DerivativeLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value of financial and nonfinancial obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 + Details
Name: | us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LiabilitiesFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of cash or securities placed with a broker or counterparty as security for a trading or derivatives securities position which was partially obtained with funds provided by the broker dealer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.8,17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_MarginDepositAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26626-111562 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Trading Securities -URI http://asc.fasb.org/extlink&oid=6526789 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.4) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_TradingSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | invest_InvestmentAxis=seb_EmergingMarketsTradingDebtMutualFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentAxis=seb_EquityMutualFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentAxis=seb_HighYieldTradingDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentAxis=seb_MoneyMarketFundsHeldInTradingAccountsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentAxis=us-gaap_CollateralizedMortgageObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentAxis=us-gaap_CorporateBondSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentAxis=us-gaap_ExchangeTradedFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CommodityContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |