Derivative Instruments and Hedging Activities Schedule of Derivative Instruments in Statement of Financial Position, Fair Value (Details) (USD $)
In Thousands, unless otherwise specified |
Mar. 31, 2013
|
Dec. 31, 2012
|
---|---|---|
Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | $ 511,749 | $ 462,080 |
Derivative Asset, Notional Amount | 10,056,328 | 9,768,656 |
Derivative Financial Instruments, Liabilities [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Liability, Fair Value, Net | (45,423) | (129,294) |
Derivative Liability, Notional Amount | 16,985,000 | 14,209,000 |
Inverse Interest-Only Securities [Member] | Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | 313,373 | 304,975 |
Derivative Asset, Notional Amount | 1,960,087 | 1,909,351 |
Inverse Interest-Only Securities [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Liability, Fair Value, Net | 0 | 0 |
Derivative Liability, Notional Amount | 0 | 0 |
Interest Rate Swap [Member] | Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | 0 | 0 |
Derivative Asset, Notional Amount | 0 | 0 |
Interest Rate Swap [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Liability, Fair Value, Net | (45,267) | (129,055) |
Derivative Liability, Notional Amount | 16,685,000 | 14,070,000 |
Credit Default Swap [Member] | Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | 47,238 | 52,906 |
Derivative Asset, Notional Amount | 437,496 | 438,440 |
Credit Default Swap [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Liability, Fair Value, Net | 0 | 0 |
Derivative Liability, Notional Amount | 0 | 0 |
Interest Rate Swaption [Member] | Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | 148,791 | 102,048 |
Derivative Asset, Notional Amount | 5,800,000 | 4,950,000 |
Interest Rate Swaption [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Liability, Fair Value, Net | 0 | 0 |
Derivative Liability, Notional Amount | 0 | 0 |
Other Contract [Member] | Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | 2,237 | 1,917 |
Derivative Asset, Notional Amount | 1,850,000 | 2,414,000 |
Other Contract [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Liability, Fair Value, Net | (156) | (239) |
Derivative Liability, Notional Amount | 300,000 | 139,000 |
Forward Purchase Commitment [Member] | Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | 110 | 234 |
Derivative Asset, Notional Amount | 8,745 | 56,865 |
Derivative Liability, Fair Value, Net | 0 | |
Derivative Liability, Notional Amount | 0 | |
Forward Purchase Commitment [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Liability, Fair Value, Net | 0 | |
Derivative Liability, Notional Amount | $ 0 |