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Available-for-Sale Securities, at Fair Value Schedule of Unrealized Loss on Investments (Details) (USD $)
In Thousands, unless otherwise specified |
Mar. 31, 2015
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Dec. 31, 2014
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| Schedule of Available-for-sale Securities [Line Items] | ||
| Available-for-Sale Securities, Number of Positions | 1,506two_AvailableForSaleSecuritiesNumberOfPositions | 1,452two_AvailableForSaleSecuritiesNumberOfPositions |
| Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year | 116us-gaap_AvailableForSaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsLessThanOneYear | 57us-gaap_AvailableForSaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsLessThanOneYear |
| Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year | 171us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsGreaterThanOrEqualToOneYear | 172us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsGreaterThanOrEqualToOneYear |
| Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | $ 1,075,418us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue | $ 413,102us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue |
| Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses | (6,006)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss | (3,146)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss |
| Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 1,276,019us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue | 1,323,688us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue |
| Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses | (22,444)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss | (32,885)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss |
| Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 2,351,437us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue | 1,736,790us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue |
| Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses | $ (28,450)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss | $ (36,031)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss |
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- Definition
This item contains disclosure of the total number of investment positions in the available-for-sale investments. No definition available.
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- Definition
Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position. 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 in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for less than twelve months. 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
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 twelve months or longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Number of investment positions in available-for-sale investments that have been in a continuous unrealized loss position for greater than or equal to a year for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement. No definition available.
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- Definition
Number of investment positions in available-for-sale investments in a continuous unrealized loss position for less than one year or normal operating cycle, if longer, for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement. No definition available.
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- Details
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