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Fair Value Measurements - Summary of Changes in Level 3 Fair Value Category (Detail) (USD $) In Thousands, unless otherwise specified | 3 Months Ended
--- | ---
Mar. 31, 2013 | Mar. 31, 2012
Level 3 [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period | $ 14,416,488 | $ 14,019,216
Additions of VIEs consolidated |  |
Included in earnings | 566,845 | 68,808
Included in other comprehensive income | (904,833) | 428,609
Purchases |  |
Issuances |  |
Sales |  |
Settlements | (688,875) | (230,319)
Transfers in Level 3 |  | (606,359)
Transfers out of Level 3 | 974,536 |
Deconsolidation of VIEs |  |
Balance, end of period | 14,364,161 | 13,679,955
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date | 564,346 | 54,256
Investments contract [Member] | Level 3 [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period | 2,261,294 | 2,199,338
Additions of VIEs consolidated |  |
Included in earnings | 297,294 | (82,816)
Included in other comprehensive income | (143,981) | 68,143
Purchases |  |
Issuances |  |
Sales |  |
Transfers in Level 3 |  |
Transfers out of Level 3 |  |
Deconsolidation of VIEs |  |
Balance, end of period | 2,414,607 | 2,184,665
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date | 297,294 | (82,816)
Loans [Member] | Level 3 [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period | 15,359,073 | 14,126,994
Additions of VIEs consolidated |  |
Included in earnings | 400,456 | 166,665
Included in other comprehensive income | (955,455) | 415,857
Purchases |  |
Issuances |  |
Sales |  |
Settlements | (687,263) | (249,439)
Transfers in Level 3 |  |
Transfers out of Level 3 |  |
Deconsolidation of VIEs |  |
Balance, end of period | 14,116,811 | 14,460,077
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date | 400,456 | 167,146
Long-term debt [Member] | Level 3 [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period | (2,956,501) | (1,934,642)
Additions of VIEs consolidated |  |
Included in earnings | (127,393) | (136,563)
Included in other comprehensive income | 193,905 | (63,205)
Purchases |  |
Issuances |  |
Sales |  |
Settlements | 4,864 | 13,030
Transfers in Level 3 |  | (665,264)
Transfers out of Level 3 | 974,536 |
Deconsolidation of VIEs |  |
Balance, end of period | (1,910,589) | (2,786,644)
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date | (127,393) | (136,563)
Investment by class [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period | 60,402 | 97,522
Included in earnings | (23) | (49)
Included in other comprehensive income | 698 | 7,814
Purchases |  |
Issuances |  |
Sales |  |
Settlements | (3,286) | (2,742)
Transfers in Level 3 |  | 58,905
Transfers out of Level 3 |  |
Balance, end of period | 57,791 | 161,450
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date |  |
Investment by class [Member] | Other Asset Backed Securities [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period | 50,264 | 75,886
Included in other comprehensive income | 569 | 8,072
Purchases |  |
Issuances |  |
Sales |  |
Settlements | (599) |
Transfers in Level 3 |  | 53,068
Transfers out of Level 3 |  |
Balance, end of period | 50,234 | 137,026
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date |  |
Investment by class [Member] | U.S. Agency Obligations [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period |  | 1,224
Included in earnings |  | (1)
Included in other comprehensive income |  | (5)
Purchases |  |
Issuances |  |
Sales |  |
Transfers in Level 3 |  |
Transfers out of Level 3 |  |
Balance, end of period |  | 1,218
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date |  |
Derivatives by class [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period | (322,337) | (486,775)
Additions of VIEs consolidated |  |
Included in earnings | (3,162) | 122,327
Included in other comprehensive income |  |
Purchases |  |
Issuances |  |
Sales |  |
Settlements | (3,190) | 8,832
Transfers in Level 3 |  |
Transfers out of Level 3 |  |
Deconsolidation of VIEs |  |
Balance, end of period | (328,689) | (355,616)
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date | (5,684) | 107,245
Investments [Member] | Level 3 [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period | 60,402 | 97,522
Additions of VIEs consolidated |  |
Included in earnings | (23) | (49)
Included in other comprehensive income | 698 | 7,814
Purchases |  |
Issuances |  |
Sales |  |
Settlements | (3,286) | (2,742)
Transfers in Level 3 |  | 58,905
Transfers out of Level 3 |  |
Deconsolidation of VIEs |  |
Balance, end of period | 57,791 | 161,450
Other assets [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Included in earnings | (327) | (756)
Other assets [Member] | Level 3 [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period | 14,557 | 16,779
Additions of VIEs consolidated |  |
Included in earnings | (327) | (756)
Purchases |  |
Issuances |  |
Sales |  |
Transfers in Level 3 |  |
Transfers out of Level 3 |  |
Deconsolidation of VIEs |  |
Balance, end of period | 14,230 | 16,023
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date | (327) | (756)
Derivatives assets [Member] | Level 3 [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period | (322,337) | (486,775)
Additions of VIEs consolidated |  |
Included in earnings | (3,162) | 122,327
Purchases |  |
Issuances |  |
Sales |  |
Settlements | (3,190) | 8,832
Transfers in Level 3 |  |
Transfers out of Level 3 |  |
Deconsolidation of VIEs |  |
Balance, end of period | (328,689) | (355,616)
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date | (5,684) | 107,245
Collateralized debt obligations [Member] | Investment by class [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period | 6,482 | 12,482
Included in earnings | (3) | (2)
Included in other comprehensive income | 113 | 101
Purchases |  |
Issuances |  |
Sales |  |
Settlements | (2,687) | (2,742)
Transfers in Level 3 |  |
Transfers out of Level 3 |  |
Balance, end of period | 3,905 | 9,839
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date |  |
Corporate obligations [Member] | Investment by class [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period | 3,656 | 7,930
Included in earnings | (20) | (46)
Included in other comprehensive income | 16 | (354)
Purchases |  |
Issuances |  |
Sales |  |
Transfers in Level 3 |  | 5,837
Transfers out of Level 3 |  |
Balance, end of period | 3,652 | 13,367
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date |  |
Interest rate swaps [Member] | Derivatives by class [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period | (108,752) | (302,177)
Additions of VIEs consolidated |  |
Included in earnings | (15,949) | 67,869
Included in other comprehensive income |  |
Purchases |  |
Issuances |  |
Sales |  |
Settlements | (681) | 12,086
Transfers in Level 3 |  |
Transfers out of Level 3 |  |
Deconsolidation of VIEs |  |
Balance, end of period | (125,382) | (222,222)
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date | (15,949) | 61,598
Credit Derivatives [Member] | Derivatives by class [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period | (213,585) | (190,653)
Additions of VIEs consolidated |  |
Included in earnings | 12,787 | (7,222)
Included in other comprehensive income |  |
Purchases |  |
Issuances |  |
Sales |  |
Settlements | (2,509) | (3,254)
Transfers in Level 3 |  |
Transfers out of Level 3 |  |
Deconsolidation of VIEs |  |
Balance, end of period | (203,307) | (201,129)
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date | 10,265 | (16,033)
Call options on long-term debt [Member] | Derivatives by class [Member] |  |
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items] |  |
Balance, beginning of period |  | 6,055
Additions of VIEs consolidated |  |
Included in earnings |  | 61,680
Included in other comprehensive income |  |
Purchases |  |
Issuances |  |
Sales |  |
Settlements |  |
Transfers in Level 3 |  |
Transfers out of Level 3 |  |
Deconsolidation of VIEs |  |
Balance, end of period |  | 67,735
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date |  | $ 61,680

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- Definition Fair value of financial instruments measured on a recurring basis using unobservable inputs removed as a result of the deconsolidation of variable interest entities. + References No definition available. + Details
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