Fair Value Measurements (Schedule of Effective Maturity Dates of Held To Maturity Investments) (Details) - USD ($) $ in Thousands |
Sep. 30, 2019 |
Dec. 31, 2018 |
|---|---|---|
| Investment maturity | ||
| Held-to-maturity maturities, Less than 1 year, Book Value | $ 498,508 | $ 585,875 |
| Held-to-maturity maturities, 1 through 5 years, Book Value | 0 | 3,859 |
| Held-to-maturity maturities, Total Book Value | 498,508 | 589,734 |
| Held-to-maturity maturities, Less than 1 year, Fair Value | 498,833 | 585,573 |
| Held-to-maturity maturities, 1 through 5 years, Fair Value | 0 | 3,859 |
| Held-to-maturity maturities, Total Fair Value | 498,833 | 589,432 |
| Available-for-sale maturity, Greater than 5 years, Book Value | 590 | 847 |
| Available-for-sale maturity, Greater than 5 years, Fair Value | $ 590 | $ 847 |
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- Definition Debt Securities, Available-For-Sale, Maturity, Allocated And Single Maturity Date, After Five Years, Amortized Cost No definition available.
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- Definition Debt Securities, Available-For-Sale, Maturity, Allocated And Single Maturity Date, after Five Years, Fair Value No definition available.
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- Definition Amount of investment in debt security measured at amortized cost (held-to-maturity). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in next fiscal year through fifth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in next fiscal year through fifth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- References No definition available.
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- Definition Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in next fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in next fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Fair value of investment in debt security measured at amortized cost (held-to-maturity). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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