XML 22 R54.htm IDEA: XBRL DOCUMENT v2.4.1.9
Pension Benefits Fair Value of Plan Assets in Heirarchy (Details) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value $ 4,864us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue $ 3,421us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue $ 2,384us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue
Defined Benefit Plan, Fair Value of Plan Assets 27,940us-gaap_DefinedBenefitPlanFairValueOfPlanAssets 24,658us-gaap_DefinedBenefitPlanFairValueOfPlanAssets 20,254us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Defined Benefit Plan, Asset Allocation 100.00%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations 100.00%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations  
Defined Benefit Plan, Target Plan Asset Allocations 100.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocations    
Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 19,908us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 3,168us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Level 3      
Defined Benefit Plan, Fair Value of Plan Assets 4,864us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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investment Purchases [Member]      
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 1,232us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3
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Investment Income [Member]      
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 144us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3
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Unrealized Investment Gain [Member]      
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 67us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3
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Cash And Money Market Funds [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Defined Benefit Plan, Asset Allocation 0.00%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
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= sm_CashAndMoneyMarketFundsMember		  
Cash And Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Cash And Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Cash And Money Market Funds [Member] | Level 3      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_InvestmentTypeAxis
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Domestic Equity Securities [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 7,569us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Defined Benefit Plan, Asset Allocation 27.10%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
/ us-gaap_InvestmentTypeAxis
= sm_DomesticEquitySecuritiesMember		 [1] 29.90%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
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Domestic Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 5,550us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Domestic Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 2,019us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Domestic Equity Securities [Member] | Level 3      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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International Equity Securities [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 3,498us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Defined Benefit Plan, Asset Allocation 12.50%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
/ us-gaap_InvestmentTypeAxis
= sm_InternationalEquitySecuritiesMember		 [2] 13.70%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
/ us-gaap_InvestmentTypeAxis
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International Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 3,498us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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International Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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International Equity Securities [Member] | Level 3      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Equity Securities [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 11,067us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Defined Benefit Plan, Asset Allocation 39.60%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
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Defined Benefit Plan, Target Plan Asset Allocations 42.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocations
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Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 9,048us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 2,019us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Equity Securities [Member] | Level 3      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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High-yield Bonds [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 797us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Defined Benefit Plan, Asset Allocation 2.90%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
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High-yield Bonds [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 797us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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High-yield Bonds [Member] | Level 3      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Fixed Income Funds [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 6,247us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Defined Benefit Plan, Asset Allocation 22.40%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
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Fixed Income Funds [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 6,247us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Floating Rate Corporate Debt [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 2,413us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Defined Benefit Plan, Asset Allocation 8.60%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
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Floating Rate Corporate Debt [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 2,413us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Floating Rate Corporate Debt [Member] | Level 3      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Defined Benefit Plan, Fair Value of Plan Assets 9,457us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 9,457us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Commodities Investment [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 810us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Defined Benefit Plan, Asset Allocation 2.90%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
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Commodities Investment [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 810us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Commodities Investment [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Commodities Investment [Member] | Level 3      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_InvestmentTypeAxis
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Real Estate Investment [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 1,327us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Defined Benefit Plan, Asset Allocation 4.70%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
/ us-gaap_InvestmentTypeAxis
= us-gaap_RealEstateInvestmentMember		 [7] 3.50%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
/ us-gaap_InvestmentTypeAxis
= us-gaap_RealEstateInvestmentMember		 [7]  
Real Estate Investment [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_InvestmentTypeAxis
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Real Estate Investment [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_InvestmentTypeAxis
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Real Estate Investment [Member] | Level 3      
Defined Benefit Plan, Fair Value of Plan Assets 1,327us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_InvestmentTypeAxis
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Hedge Funds [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 4,130us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_InvestmentTypeAxis
= us-gaap_HedgeFundsMember		 [8]  
Defined Benefit Plan, Asset Allocation 14.80%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
/ us-gaap_InvestmentTypeAxis
= us-gaap_HedgeFundsMember		 [8] 14.30%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
/ us-gaap_InvestmentTypeAxis
= us-gaap_HedgeFundsMember		 [8]  
Hedge Funds [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 593us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_InvestmentTypeAxis
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Hedge Funds [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_InvestmentTypeAxis
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Hedge Funds [Member] | Level 3      
Defined Benefit Plan, Fair Value of Plan Assets 3,537us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_InvestmentTypeAxis
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Collective Investment Trust [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 1,149us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_InvestmentTypeAxis
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Defined Benefit Plan, Asset Allocation 4.10%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
/ us-gaap_InvestmentTypeAxis
= sm_CollectiveInvestmentTrustMember		 [9] 2.60%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
/ us-gaap_InvestmentTypeAxis
= sm_CollectiveInvestmentTrustMember		 [9]  
Collective Investment Trust [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Collective Investment Trust [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 1,149us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_InvestmentTypeAxis
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Collective Investment Trust [Member] | Level 3      
Defined Benefit Plan, Fair Value of Plan Assets 0us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Other Investments [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 7,416us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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Other Investments [Member] | Fair Value, Inputs, Level 1 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 1,403us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_InvestmentTypeAxis
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Other Investments [Member] | Fair Value, Inputs, Level 2 [Member]      
Defined Benefit Plan, Fair Value of Plan Assets 1,149us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_InvestmentTypeAxis
= us-gaap_OtherInvestmentsMember		  
Other Investments [Member] | Level 3      
Defined Benefit Plan, Fair Value of Plan Assets $ 4,864us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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/ us-gaap_InvestmentTypeAxis
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Other than Securities Investment [Member]      
Defined Benefit Plan, Asset Allocation 26.50%us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
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Defined Benefit Plan, Target Plan Asset Allocations 23.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocations
/ us-gaap_InvestmentTypeAxis
= us-gaap_OtherThanSecuritiesInvestmentMember		    
[1] Level 1 equity securities consist of United States large and small capitalization companies, which are actively traded securities that can be sold upon demand. Level 2 equity securities are investments in a collective investment fund that is valued at net asset value based on the value of the underlying investments and total units outstanding on a daily basis. The objective of this fund is to approximate the S&P 500 by investing in one or more collective investment funds.
[2] International equity securities consists of a well-diversified portfolio of holdings of mostly large issuers organized in developed countries with liquid markets, commingled with investments in equity securities of issuers located in emerging markets and believed to have strong sustainable financial productivity at attractive valuations.
[3] High-yield bonds consist of non-investment grade fixed income securities. The investment objective is to obtain high current income. Due to the increased level of default risk, security selection focuses on credit-risk analysis.
[4] The objective is to achieve value added from sector or issue selection by constructing a portfolio to approximate the investment results of the Barclay's Capital Aggregate Bond Index with a modest amount of variability in duration around the index.
[5] Investments consist of floating rate bank loans. The interest rates on these loans are typically reset on a periodic basis to account for changes in the level of interest rates.
[6] Investments with exposure to commodity price movements, primarily through the use of futures, swaps and other commodity-linked securities.
[7] The investment objective of direct real estate is to provide current income with the potential for long-term capital appreciation. Ownership in real estate entails a long-term time horizon, periodic valuations, and potentially low liquidity.
[8] The hedge fund portfolio includes an investment in an actively traded global mutual fund that focuses on alternative investments and a hedge fund of funds that invests both long and short using a variety of investment strategies.
[9] (9)Collective investment trusts invest in short-term investments and are valued at the net asset value of the collective investment trust. The net asset value, as provided by the trustee, is used as a practical expedient to estimate fair value. The net asset value is based on the fair value of the underlying investments held by the fund less its liabilities.