|
Derivative Instruments and Hedging Activities Interest Rate Sensitive Assets/Liabilities (Details) (USD $)
In Thousands, unless otherwise specified |
Sep. 30, 2013
|
Dec. 31, 2012
|
|---|---|---|
| Derivatives, Fair Value [Line Items] | ||
| Available-for-sale Securities, Interest-only | $ 89,080 | $ 77,342 |
|
Derivative Financial Instruments, Assets [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Fair Value, Net | 544,515 | 462,080 |
| Derivative, Notional Amount | 27,657,236 | 9,768,656 |
|
Derivative Financial Instruments, Liabilities [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Fair Value, Net | (73,827) | (129,294) |
| Derivative, Notional Amount | 13,709,165 | 14,209,000 |
|
Forward Contracts [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Notional Amount | 857,000 | 953,000 |
| Derivative, Cost | 1,057,523 | 1,009,996 |
|
Forward Contracts [Member] | Derivative Financial Instruments, Assets [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Fair Value, Net | 21,896 | 1,917 |
| Derivative, Notional Amount | 1,504,000 | 2,414,000 |
|
Forward Contracts [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Fair Value, Net | (34,634) | (239) |
| Derivative, Notional Amount | 4,247,000 | 139,000 |
|
Options Held [Member] | Derivative Financial Instruments, Assets [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Fair Value, Net | 6,630 | |
| Derivative, Notional Amount | 2,500,000 | |
|
Options Held [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Fair Value, Net | 0 | |
| Derivative, Notional Amount | 0 | |
|
Forward Purchase Commitment [Member] | Derivative Financial Instruments, Assets [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Fair Value, Net | 234 | |
| Derivative, Notional Amount | 56,865 | |
|
Forward Purchase Commitment [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Fair Value, Net | 0 | |
| Derivative, Notional Amount | 0 | |
|
Long [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Agency To-be-Announced Securities, Notional Amount, Mitigate Prepayment Exposure | 654,000 | |
|
Long [Member] | Forward Contracts [Member]
|
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| Derivatives, Fair Value [Line Items] | ||
| Agency To-be-Announced Securities, Notional Amount, Non-Risk Management | 2,650,000 | |
| Derivative, Notional Amount | 3,304,000 | 1,753,000 |
| Derivative, Cost | 3,509,122 | 1,867,621 |
|
Long [Member] | Forward Contracts [Member] | Derivative Financial Instruments, Assets [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Fair Value, Net | 21,896 | 1,729 |
|
Long [Member] | Forward Contracts [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Fair Value, Net | (601) | (239) |
|
Long [Member] | Options Held [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Notional Amount | 2,500,000 | |
| Derivative, Cost | (17,266) | |
|
Short [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Agency To-be-Announced Securities, Notional Amount, Mitigate Prepayment Exposure | 2,447,000 | |
|
Short [Member] | Forward Contracts [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Notional Amount | (2,447,000) | (800,000) |
| Derivative, Cost | (2,451,599) | (857,625) |
|
Short [Member] | Forward Contracts [Member] | Derivative Financial Instruments, Assets [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Fair Value, Net | 0 | 188 |
|
Short [Member] | Forward Contracts [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
| Derivatives, Fair Value [Line Items] | ||
| Derivative, Fair Value, Net | $ (34,033) | $ 0 |