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Summary of Significant Accounting Policies - Fair Value Hierarchy for Financial Assets (Detail) (Recurring, USD $) In Thousands, unless otherwise specified | Apr. 04, 2015 | Jan. 03, 2015
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Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Adjusted Basis Cost | $ 135,720 us-gaap_AvailableForSaleSecuritiesAmortizedCost | $ 134,453 us-gaap_AvailableForSaleSecuritiesAmortizedCost
Gross Unrealized Gains | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax
Gross Unrealized (Losses) | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax
Estimated Fair Value | 135,720 us-gaap_AvailableForSaleSecurities | 134,453 us-gaap_AvailableForSaleSecurities
Cash and Cash Equivalents | 135,720 us-gaap_CashCashEquivalentsAndShortTermInvestments | 134,453 us-gaap_CashCashEquivalentsAndShortTermInvestments
Cash |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Adjusted Basis Cost | 78,308 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_CashMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 92,888 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_CashMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Gross Unrealized Gains |  | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CashMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Gross Unrealized (Losses) | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CashMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CashMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Estimated Fair Value | 78,308 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CashMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 92,888 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CashMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Cash and Cash Equivalents | 78,308 us-gaap_CashCashEquivalentsAndShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_CashMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 92,888 us-gaap_CashCashEquivalentsAndShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_CashMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Level 1: |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Adjusted Basis Cost | 57,412 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 41,565 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Gross Unrealized Gains | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Gross Unrealized (Losses) | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Estimated Fair Value | 57,412 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 41,565 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Cash and Cash Equivalents | 57,412 us-gaap_CashCashEquivalentsAndShortTermInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 41,565 us-gaap_CashCashEquivalentsAndShortTermInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Level 1: | Bank Time Deposits |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Adjusted Basis Cost | 43,500 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_BankTimeDepositsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 40,500 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_BankTimeDepositsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Gross Unrealized Gains | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_BankTimeDepositsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_BankTimeDepositsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Gross Unrealized (Losses) | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_BankTimeDepositsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_BankTimeDepositsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Estimated Fair Value | 43,500 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_BankTimeDepositsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 40,500 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_BankTimeDepositsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Cash and Cash Equivalents | 43,500 us-gaap_CashCashEquivalentsAndShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_BankTimeDepositsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 40,500 us-gaap_CashCashEquivalentsAndShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_BankTimeDepositsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Level 1: | U.S. Treasuries |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Adjusted Basis Cost | 0 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_USTreasurySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_USTreasurySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Gross Unrealized Gains | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_USTreasurySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_USTreasurySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Gross Unrealized (Losses) | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_USTreasurySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_USTreasurySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Estimated Fair Value | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USTreasurySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USTreasurySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Cash and Cash Equivalents | 0 us-gaap_CashCashEquivalentsAndShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_USTreasurySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 us-gaap_CashCashEquivalentsAndShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_USTreasurySecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Level 1: | Money Market Funds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Adjusted Basis Cost | 13,912 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 1,065 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Gross Unrealized Gains | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Gross Unrealized (Losses) | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Estimated Fair Value | 13,912 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 1,065 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Cash and Cash Equivalents | 13,912 us-gaap_CashCashEquivalentsAndShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 1,065 us-gaap_CashCashEquivalentsAndShortTermInvestments / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Level 2: |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Adjusted Basis Cost | 0 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Gross Unrealized Gains | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Gross Unrealized (Losses) | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Estimated Fair Value | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Cash and Cash Equivalents | 0 us-gaap_CashCashEquivalentsAndShortTermInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 us-gaap_CashCashEquivalentsAndShortTermInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Level 3: |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Adjusted Basis Cost | 0 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Gross Unrealized Gains | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Gross Unrealized (Losses) | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 masi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedLossbeforeTax / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Estimated Fair Value | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember
Cash and Cash Equivalents | $ 0 us-gaap_CashCashEquivalentsAndShortTermInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember | $ 0 us-gaap_CashCashEquivalentsAndShortTermInvestments / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember

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- 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
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- Definition This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + 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 210.5-02.2) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash -URI http://asc.fasb.org/extlink&oid=6506951 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash Equivalents -URI http://asc.fasb.org/extlink&oid=6507016 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.1) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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