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Derivative Instruments and Hedging Activities Schedule of TBA Contracts (Details) (USD $)
In Thousands, unless otherwise specified |
Mar. 31, 2014
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Dec. 31, 2013
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|---|---|---|
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Derivative Financial Instruments, Assets [Member]
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| Derivative [Line Items] | ||
| Derivative, Notional Amount | $ 45,175,522 | $ 30,383,908 |
| Derivative, Fair Value, Net | 429,419 | 549,859 |
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Derivative Financial Instruments, Liabilities [Member]
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| Derivative [Line Items] | ||
| Derivative, Notional Amount | 2,894,624 | 10,876,702 |
| Derivative, Fair Value, Net | (8,395) | (22,081) |
|
Long [Member]
|
||
| Derivative [Line Items] | ||
| Agency To-be-Announced Securities, Notional Amount, Mitigate Prepayment Exposure | 1,225,000 | 400,000 |
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Short [Member]
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| Derivative [Line Items] | ||
| Agency To-be-Announced Securities, Notional Amount, Mitigate Prepayment Exposure | 2,247,000 | 1,947,000 |
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Forward Contracts [Member]
|
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| Derivative [Line Items] | ||
| Derivative, Notional Amount | (1,022,000) | 603,000 |
| Derivative, Cost | (1,086,572) | 790,392 |
| Derivative, Market Value | (1,087,728) | 823,693 |
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Forward Contracts [Member] | Derivative Financial Instruments, Assets [Member]
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| Derivative [Line Items] | ||
| Derivative, Notional Amount | 1,100,000 | 4,097,000 |
| Derivative, Fair Value, Net | 4,331 | 33,425 |
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Forward Contracts [Member] | Derivative Financial Instruments, Liabilities [Member]
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| Derivative [Line Items] | ||
| Derivative, Notional Amount | 2,372,000 | 400,000 |
| Derivative, Fair Value, Net | (5,487) | (125) |
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Forward Contracts [Member] | Long [Member]
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| Derivative [Line Items] | ||
| Derivative, Notional Amount | 1,225,000 | 2,550,000 |
| Derivative, Cost | 1,183,028 | 2,749,648 |
| Derivative, Market Value | 1,186,866 | 2,767,295 |
| Agency To-be-Announced Securities, Notional Amount, Non-Risk Management | 2,150,000 | |
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Forward Contracts [Member] | Long [Member] | Derivative Financial Instruments, Assets [Member]
|
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| Derivative [Line Items] | ||
| Derivative, Fair Value, Net | 4,331 | 17,771 |
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Forward Contracts [Member] | Long [Member] | Derivative Financial Instruments, Liabilities [Member]
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| Derivative [Line Items] | ||
| Derivative, Fair Value, Net | (493) | (125) |
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Forward Contracts [Member] | Short [Member]
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| Derivative [Line Items] | ||
| Derivative, Notional Amount | (2,247,000) | (1,947,000) |
| Derivative, Cost | (2,269,600) | (1,959,256) |
| Derivative, Market Value | (2,274,594) | (1,943,602) |
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Forward Contracts [Member] | Short [Member] | Derivative Financial Instruments, Assets [Member]
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| Derivative [Line Items] | ||
| Derivative, Fair Value, Net | 0 | 15,654 |
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Forward Contracts [Member] | Short [Member] | Derivative Financial Instruments, Liabilities [Member]
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| Derivative [Line Items] | ||
| Derivative, Fair Value, Net | $ (4,994) | $ 0 |