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Financial Instruments - Additional Information (Detail) (USD $)
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12 Months Ended | |
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Dec. 31, 2014
debt_security
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Dec. 31, 2013
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| Debt Instrument [Line Items] | ||
| Number of corporate debt securities in an unrealized loss position | 23us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1 | |
| Fair value of corporate debt in an unrealized loss position | $ 35,800,000us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue | |
| Available-for-sale securities, gross unrealized loss accumulated in investments | 50,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax | 9,000us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax |
| Transfer of securities, Level 1 | 0us-gaap_FairValueAssetsLevel1ToLevel2TransfersAmount | |
| Transfer of securities, Level 2 | 0us-gaap_FairValueAssetsLevel2ToLevel1TransfersAmount | |
| Transfer of securities, Level 3 | $ 0us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet | |
| Minimum [Member] | ||
| Debt Instrument [Line Items] | ||
| Due date of company's long term available for sale securities | 1 year | |
| Fair Value Inputs, Discount Rate |
0.33%us-gaap_FairValueInputsDiscountRate / us-gaap_RangeAxis = us-gaap_MinimumMember |
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| Maximum [Member] | ||
| Debt Instrument [Line Items] | ||
| Period of unrealized loss position | 12 months | |
| Due date of company's long term available for sale securities | 2 years | |
| Fair Value Inputs, Discount Rate |
0.54%us-gaap_FairValueInputsDiscountRate / us-gaap_RangeAxis = us-gaap_MaximumMember |
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- Definition
Available for sale securities noncurrent maturity period. No definition available.
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- Definition
Period of unrealized loss position. No definition available.
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- Definition
Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Amount of transfers of assets measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of transfer of financial instrument classified as an asset into (out of) level 3 of the fair value hierarchy. No definition available.
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- Details
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- Details
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