Consolidated Statements Of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Premiums, fees and reimbursements received	$ 12	$ 12
Investment income received	41	66
Financial guarantee losses and loss adjustment expenses paid	(77)	(115)
Proceeds from recoveries and reinsurance	49	27
Proceeds from loan repurchase commitments	600	0
Operating and employee related expenses paid	(43)	(46)
Interest paid, net of interest converted to principal	(37)	(47)
Income taxes (paid) received	0	14
Net cash provided (used) by operating activities	545	(89)
Cash flows from investing activities:
Purchases of available-for-sale investments	(671)	(574)
Sales of available-for-sale investments	396	569
Paydowns and maturities of available-for-sale investments	330	464
Purchases of investments at fair value	(103)	(85)
Sales, paydowns, maturities and other proceeds of investments at fair value	108	88
Sales, paydowns and maturities (purchases) of short-term investments, net	(138)	172
Sales, paydowns and maturities of held-to-maturity investments	0	315
Paydowns and maturities of loans receivable	25	7
(Payments) proceeds for derivative settlements	(57)	(7)
Collateral (to) from counterparties	0	(8)
Net cash provided (used) by investing activities	(110)	941
Cash flows from financing activities:
Proceeds from investment agreements	0	7
Principal paydowns of investment agreements	(2)	(20)
Principal paydowns of medium-term notes	(49)	0
Principal paydowns of variable interest entity notes	(203)	(327)
Purchases of treasury stock	(1)	(134)
Other financing	0	(7)
Net cash provided (used) by financing activities	(255)	(481)
Net increase (decrease) in cash and cash equivalents	180	371
Cash and cash equivalents - beginning of period	167	83
Cash and cash equivalents - end of period	347	454
Reconciliation of net income (loss) to net cash provided (used) by operating activities:
Net income (loss)	(167)	(439)
Change in:
Premiums receivable	9	10
Unearned premium revenue	(33)	(38)
Loss and loss adjustment expense reserves	(40)	133
Insurance loss recoverable	116	151
Loan repurchase commitments	604	0
Accrued interest payable	52	68
Net (gains) losses on financial instruments at fair value and foreign exchange	(21)	1
Other net realized (gains) losses	5	(14)
Other operating	20	39
Total adjustments to net income (loss)	712	350
Net cash provided (used) by operating activities	$ 545	$ (89)