Consolidated Statements Of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Premiums, fees and reimbursements received	$ 36	$ 20
Investment income received	60	96
Financial guarantee losses and loss adjustment expenses paid	(315)	(461)
Proceeds from recoveries and reinsurance	91	69
Proceeds from loan repurchase commitments	600	0
Operating and employee related expenses paid	(65)	(58)
Interest paid, net of interest converted to principal	(48)	(67)
Income taxes (paid) received	0	13
Net cash provided (used) by operating activities	359	(388)
Cash flows from investing activities:
Purchases of available-for-sale investments	(811)	(900)
Sales of available-for-sale investments	469	862
Paydowns and maturities of available-for-sale investments	482	613
Purchases of investments at fair value	(159)	(137)
Sales, paydowns, maturities and other proceeds of investments at fair value	136	139
Sales, paydowns and maturities (purchases) of short-term investments, net	(94)	77
Sales, paydowns and maturities of held-to-maturity investments	0	315
Paydowns and maturities of loans receivable	75	11
(Payments) proceeds for derivative settlements	(61)	(12)
Net cash provided (used) by investing activities	37	968
Cash flows from financing activities:
Proceeds from investment agreements	2	10
Principal paydowns of investment agreements	(1)	(21)
Principal paydowns of medium-term notes	(77)	0
Principal paydowns of variable interest entity notes	(370)	(333)
Principal paydowns of long-term debt	(4)	0
Purchases of treasury stock	(1)	(200)
Other financing	0	(8)
Net cash provided (used) by financing activities	(451)	(552)
Net increase (decrease) in cash and cash equivalents	(55)	28
Cash and cash equivalents - beginning of period	167	83
Cash and cash equivalents - end of period	112	111
Reconciliation of net income (loss) to net cash provided (used) by operating activities:
Net income (loss)	(290)	(497)
Change in:
Premiums receivable	24	13
Unearned premium revenue	(72)	(53)
Loss and loss adjustment expense reserves	(140)	101
Insurance loss recoverable	140	(105)
Loan repurchase commitments	604	0
Accrued interest payable	81	102
Accrued expenses	5	25
Net (gains) losses on financial instruments at fair value and foreign exchange	(35)	(8)
Other net realized (gains) losses	14	(37)
Other operating	28	71
Total adjustments to net income (loss)	649	109
Net cash provided (used) by operating activities	$ 359	$ (388)