Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Premiums, fees and reimbursements received	$ 44	$ 28	$ 47
Investment income received	77	118	176
Insured derivative commutations and losses paid	0	(1)	(11)
Financial guarantee losses and loss adjustment expenses paid	(343)	(475)	(489)
Proceeds from recoveries and reinsurance	282	84	155
Proceeds from loan repurchase commitments	600	0	0
Operating expenses paid and other operating	(88)	(73)	(77)
Interest paid, net of interest converted to principal	(61)	(84)	(180)
Income taxes (paid) received	0	13	11
Net cash provided (used) by operating activities	511	(390)	(368)
Cash flows from investing activities:
Purchases of available-for-sale investments	(1,163)	(1,133)	(2,140)
Sales of available-for-sale investments	597	1,095	2,195
Paydowns and maturities of available-for-sale investments	626	724	857
Purchases of investments at fair value	(206)	(179)	(151)
Sales, paydowns and maturities of investments at fair value	174	198	617
Sales, paydowns and maturities (purchases) of short-term investments, net	(99)	143	(157)
Sales, paydowns and maturities of held-to-maturity investments	0	890	0
Paydowns and maturities of loans receivable and other instruments at fair value	77	16	74
Consolidation of variable interest entities	0	0	72
Deconsolidation of variable interest entities	0	0	(2)
(Payments) proceeds for derivative settlements	(66)	(16)	(98)
Capital expenditures	(1)	0	0
Net cash provided (used) by investing activities	(61)	1,738	1,267
Cash flows from financing activities:
Proceeds from investment agreements	2	12	15
Principal paydowns of investment agreements	(2)	(48)	(25)
Principal paydowns of medium-term notes	(81)	0	(57)
Principal paydowns of variable interest entity notes	(369)	(914)	(765)
Principal paydowns of long-term debt	(6)	(115)	(150)
Purchases of treasury stock	(1)	(200)	(106)
Other financing	0	0	(8)
Net cash provided (used) by financing activities	(457)	(1,265)	(1,096)
Effect of exchange rate changes on cash and cash equivalents	0	1	0
Net increase (decrease) in cash and cash equivalents	(7)	84	(197)
Cash and cash equivalents—beginning of year	167	83	280
Cash and cash equivalents—end of year	160	167	83
Reconciliation of net income (loss) to net cash provided (used) by operating activities:
Net income (loss)	(445)	(578)	(359)
Change in:
Premiums receivable	31	29	62
Deferred acquisition costs	8	10	12
Accrued investment income	0	6	20
Unearned premium revenue	(83)	(77)	(105)
Loss and loss adjustment expense reserves	(102)	86	0
Insurance loss recoverable	381	16	(99)
Loan repurchase commitments	604	0	0
Accrued interest payable	107	133	106
Accrued expenses	4	34	12
Net investment losses related to other-than-temporary impairments	0	0	67
Unrealized (gains) losses on insured derivatives	0	(7)	(25)
Net (gains) losses on financial instruments at fair value and foreign exchange	(40)	(70)	(157)
Other net realized (gains) losses	21	(37)	58
Deferred income tax provision (benefit)	0	12	13
Interest on variable interest entities, net	3	6	(3)
Other operating	22	47	30
Total adjustments to net income (loss)	956	188	(9)
Net cash provided (used) by operating activities	$ 511	$ (390)	$ (368)