Derivative Instruments and Hedging Activities Interest Spread on Interest Rate Swaps (Details) - USD ($) |
3 Months Ended | |
|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
|
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Average Notional Amount | $ 26,619,080,000 | $ 16,574,247,000 |
| Interest Rate Swap [Member] | ||
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Interest Expense on Interest Rate Swap and Swaption Agreements | 3,809,000 | (7,904,000) |
| Net Long Position [Member] | Interest Rate Swap [Member] | ||
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Average Notional Amount | $ 27,751,460,922 | $ 18,707,666,067 |
| X | ||||||||||
- Definition Average notional amount during the period presented specified by the derivative(s). No definition available.
|
| X | ||||||||||
- Definition Net interest spread on interest rate swap and swaption agreements, at fair value. No definition available.
|
| X | ||||||||||
- 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.
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|