Consolidated Statements Of Cash Flows (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Premiums, fees and reimbursements received	$ 54	$ 53
Investment income received	115	162
Insured derivative losses and commutations paid		(20)
Financial guarantee losses and loss adjustment expenses paid	(115)	(172)
Proceeds from reinsurance and recoveries	13	16
Operating and employee related expenses paid	(84)	(120)
Interest paid, net of interest converted to principal	(61)	(149)
Income taxes (paid) received		(3)
Net cash provided (used) by operating activities	(78)	(233)
Cash flows from investing activities:
Purchase of fixed-maturity securities	(673)	(938)
Sale and redemption of fixed-maturity securities	1,062	1,440
Proceeds from paydowns on variable interest entity loans	69	60
Redemptions of held-to-maturity investments	4	750
Sale (purchase) of short-term investments, net	(130)	(115)
Sale (purchase) of other investments, net	(1)	65
(Payments) proceeds for derivative settlements	(31)	(51)
Collateral (to) from swap counterparty	23
Capital expenditures		(1)
Net cash provided (used) by investing activities	323	1,210
Cash flows from financing activities:
Proceeds from investment agreements	8	16
Payments for drawdowns of investment agreements	(39)	(18)
Issuance of medium-term notes		8
Principal paydowns of medium-term notes	(23)
Principal paydowns of variable interest entity notes	(246)	(262)
Payments for securities sold under agreements to repurchase		(138)
Payments for retirement of debt	(1)	(361)
Net cash provided (used) by financing activities	(301)	(755)
Net increase (decrease) in cash and cash equivalents	(56)	222
Cash and cash equivalents-beginning of period	990	633
Cash and cash equivalents-end of period	934	855
Reconciliation of net income (loss) to net cash provided (used) by operating activities:
Net income (loss)	164	10
Change in:
Premiums receivable	44	37
Deferred acquisition costs	12	11
Unearned premium revenue	(130)	(149)
Loss and loss adjustment expense reserves	(68)	31
Insurance loss recoverable	(229)	(91)
Current income taxes	(1)	(24)
Net investment losses related to other-than-temporary impairments		94
Unrealized (gains) losses on insured derivatives	73	(303)
Net (gains) losses on financial instruments at fair value and foreign exchange	(96)	46
Deferred income tax provision (benefit)	53	32
(Gains) losses on extinguishment of debt	(4)
Other operating	104	73
Total adjustments to net income (loss)	(242)	(243)
Net cash provided (used) by operating activities	$ (78)	$ (233)