Derivative Instruments and Hedging Activities Schedule of Derivative Instruments in Statement of Financial Position, Fair Value (Details) (USD $)
In Thousands, unless otherwise specified |
Jun. 30, 2012
|
Dec. 31, 2011
|
---|---|---|
Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | $ 361,073 | $ 251,856 |
Derivative Asset, Notional Amount | 6,563,915 | 4,855,985 |
Derivative Financial Instruments, Liabilities [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Liability, Fair Value, Net | (82,619) | (49,080) |
Derivative Liability, Notional Amount | 9,218,591 | 6,814,812 |
Inverse Interest-Only Securities [Member] | Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | 280,672 | 157,421 |
Derivative Asset, Notional Amount | 1,131,084 | |
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 | |
Interest Rate Swap [Member] | Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | 0 | |
Derivative Asset, Notional Amount | 0 | |
Interest Rate Swap [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Liability, Fair Value, Net | (28,790) | |
Derivative Liability, Notional Amount | 5,810,000 | |
Credit Default Swap [Member] | Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | 86,136 | |
Derivative Asset, Notional Amount | 544,699 | |
Credit Default Swap [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Liability, Fair Value, Net | (14,638) | |
Derivative Liability, Notional Amount | 154,812 | |
Interest Rate Swaption [Member] | Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | 5,635 | |
Derivative Asset, Notional Amount | 2,900,000 | |
Interest Rate Swaption [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Liability, Fair Value, Net | 0 | |
Derivative Liability, Notional Amount | 0 | |
Other Contract [Member] | Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | 0 | 2,664 |
Derivative Asset, Notional Amount | 275,000 | |
Other Contract [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Liability, Fair Value, Net | (5,652) | |
Derivative Liability, Notional Amount | 850,000 | |
Forward Purchase Commitment [Member] | Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | 0 | 0 |
Derivative Asset, Notional Amount | 32,406 | 0 |
Forward Purchase Commitment [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Liability, Fair Value, Net | 0 | 0 |
Derivative Liability, Notional Amount | 0 | 0 |
Forward Sale Commitment [Member] | Derivative Financial Instruments, Assets [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Asset, Fair Value, Net | 0 | |
Derivative Asset, Notional Amount | 5,202 | |
Forward Sale Commitment [Member] | Derivative Financial Instruments, Liabilities [Member]
|
||
Derivatives, Fair Value [Line Items] | ||
Derivative Liability, Fair Value, Net | 0 | |
Derivative Liability, Notional Amount | $ 0 |