Consolidated Statements Of Cash Flows (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operating activities:
Premiums, fees and reimbursements received	$ 107	$ 160
Investment income received	223	316
Insured derivative commutations and losses paid	(419)	(463)
Financial guarantee losses and loss adjustment expenses paid	(227)	(363)
Proceeds from recoveries and reinsurance	1,781	38
Operating and employee related expenses paid	(176)	(232)
Interest paid, net of interest converted to principal	(118)	(241)
Income taxes (paid) received	0	(5)
Net cash provided (used) by operating activities	1,171	(790)
Cash flows from investing activities:
Purchase of fixed-maturity securities	(1,675)	(1,587)
Sale and redemption of fixed-maturity securities	2,544	3,376
Proceeds from paydowns on variable interest entity loans	137	131
Redemptions of held-to-maturity investments	12	792
Sale (purchase) of short-term investments, net	(1,267)	122
Sale (purchase) of other investments, net	(1)	76
Consolidation (deconsolidation) of variable interest entities, net	(26)	(51)
(Payments) proceeds for derivative settlements	(39)	(83)
Collateral (to) from swap counterparty	63	(327)
Capital expenditures	(1)	(4)
Net cash provided (used) by investing activities	(253)	2,445
Cash flows from financing activities:
Proceeds from investment agreements	15	33
Payments for drawdowns of investment agreements	(190)	(432)
Issuance of medium-term notes	0	13
Principal paydowns of medium-term notes	(40)	(42)
Principal paydowns of variable interest entity notes	(685)	(797)
Payments for securities sold under agreements to repurchase	0	(287)
Payments for retirement of debt	(2)	(363)
Purchase of treasury stock	0	0
Contribution from noncontrolling interest and redemption of subsidiary preferred stock, net	0	0
Restricted stock awards settlements, net	0	1
Net cash provided (used) by financing activities	(902)	(1,874)
Net increase (decrease) in cash and cash equivalents	16	(219)
Cash and cash equivalents - beginning of period	990	633
Cash and cash equivalents - end of period	1,006	414
Reconciliation of net income (loss) to net cash provided (used) by operating activities:
Net income (loss)	(14)	591
Change in: [Abstract]
Premiums receivable	91	96
Deferred acquisition costs	24	27
Unearned premium revenue	(265)	(311)
Loss and loss adjustment expense reserves	(79)	(2)
Insurance loss recoverable	2,754	(166)
Accrued expenses	95	5
Net investment losses related to other-than-temporary impairments	0	97
Unrealized (gains) losses on insured derivatives	(1,277)	(1,506)
Net (gains) losses on financial instruments at fair value and foreign exchange	(168)	86
Deferred income tax provision (benefit)	(37)	230
(Gains) losses on extinguishment of debt	(43)	(33)
Other operating	90	96
Total adjustments to net income (loss)	1,185	(1,381)
Net Cash Provided By Used In Operating Activities	$ 1,171	$ (790)