Consolidated Statements Of Operations - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Change in fair value of insured derivatives:
Unrealized gains (losses) on insured derivatives			$ 0	$ 121
Net change in fair value of insured derivatives	$ 16	$ 3	(20)	91
Net gains (losses) on financial instruments at fair value and foreign exchange	38	(55)	(17)	20
Net investment losses related to other-than-temporary impairments:
Net investment losses related to other-than-temporary impairments	0	(3)	(1)	(10)
Net gains (losses) on extinguishment of debt	0	0	5	(1)
Other net realized gains (losses)	(2)	(1)	(3)	18
Total revenues	203	92	353	556
Expenses:
Losses and loss adjustment	50	39	149	79
Interest	49	49	148	149
Total expenses	148	147	454	406
Income (loss) before income taxes	55	(55)	(101)	150
Provision (benefit) for income taxes	24	(20)	(28)	52
Net income (loss)	$ 31	$ (35)	$ (73)	$ 98
Net income (loss) per common share:
Basic	$ 0.23	$ (0.23)	$ (0.55)	$ 0.56
Diluted	$ 0.23	$ (0.23)	$ (0.55)	$ 0.55
Weighted average number of common shares outstanding:
Basic	131,633,411	155,239,723	133,368,752	169,610,370
Diluted	132,042,067	155,239,723	133,368,752	170,566,386
Non Variable Interest Entity [Member]
Premiums earned:
Scheduled premiums earned	$ 42	$ 47	$ 131	$ 153
Refunding premiums earned	35	37	94	123
Premiums earned (net of ceded premiums of $2, $2, $5 and $7)	77	84	225	276
Net investment income	39	38	115	112
Fees and reimbursements	22	1	24	4
Change in fair value of insured derivatives:
Realized gains (losses) and other settlements on insured derivatives	(4)	(18)	(20)	(30)
Unrealized gains (losses) on insured derivatives	20	21	0	121
Net change in fair value of insured derivatives	16	3	(20)	91
Net gains (losses) on financial instruments at fair value and foreign exchange	38	(55)	(17)	20
Net investment losses related to other-than-temporary impairments:
Investment losses related to other-than-temporary impairments	0	(1)	(1)	(10)
Other-than-temporary impairments recognized in accumulated other comprehensive income (loss)	0	(2)	0	0
Net investment losses related to other-than-temporary impairments	0	(3)	(1)	(10)
Net gains (losses) on extinguishment of debt	0	0	5	(1)
Other net realized gains (losses)	(2)	(1)	(3)	18
Expenses:
Losses and loss adjustment	50	39	149	79
Amortization of deferred acquisition costs	10	11	30	37
Operating	32	35	97	102
Interest	49	49	148	149
Variable Interest Entity Primary Beneficiary [Member]
Premiums earned:
Net investment income	5	12	25	37
Change in fair value of insured derivatives:
Net gains (losses) on financial instruments at fair value and foreign exchange	8	13	0	9
Expenses:
Operating	3	3	10	10
Interest	$ 4	$ 10	$ 20	$ 29