Derivative Instruments and Hedging Activities Short U.S. Treasury Securities (Details) - USD ($) |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|---|---|---|---|
| Derivative [Line Items] | |||
| Notional | $ 36,528,169,000 | $ 31,226,878,000 | $ 18,802,500,000 |
| Derivative Financial Instruments, Liabilities [Member] | |||
| Derivative [Line Items] | |||
| Notional | 5,403,265,000 | 8,335,507,000 | |
| Fair Value | (820,590,000) | (31,903,000) | |
| Short US Treasury Securities [Member] | |||
| Derivative [Line Items] | |||
| Fair Value | (781,500,000) | 0 | |
| Short US Treasury Securities [Member] | Derivative Financial Instruments, Liabilities [Member] | |||
| Derivative [Line Items] | |||
| Fair Value | (781,455,000) | 0 | |
| Short US Treasury Securities [Member] | Short [Member] | |||
| Derivative [Line Items] | |||
| Notional | $ 800,000,000.0 | $ 0 |
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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Fair value of the assets less the liabilities of a derivative or group of derivatives. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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