Reinsurance and Other Monoline Exposures (Details) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012		Dec. 31, 2012	Sep. 30, 2013 AG Re	Feb. 14, 2013 AG Re	Sep. 30, 2013 AGC
Exposure, Premium Receivable, and Loss and LAE by Reinsurer
Fair market value of company's pledged securities	$ 681,000,000				$ 681,000,000				$ 660,000,000	$ 314,000,000	$ 27,000,000	$ 130,000,000
Additional ceding commission										7,000,000
Commutations							108,000,000
Increase (Decrease) in Net Par Due to Commutations							19,100,000,000
Commutation gains (losses)							84,000,000
Premiums Written:
Direct	28,000,000		24,000,000		48,000,000		131,000,000
Assumed	(2,000,000)	[1]	0	[1]	17,000,000	[1]	13,000,000	[1]
Ceded	4,000,000	[2]	1,000,000	[2]	3,000,000	[2]	88,000,000	[2]
Net	30,000,000		25,000,000		68,000,000		232,000,000
Premiums Earned:
Direct	173,000,000		242,000,000		627,000,000		694,000,000
Assumed	12,000,000		13,000,000		26,000,000		39,000,000
Ceded	(26,000,000)		(33,000,000)		(83,000,000)		(98,000,000)
Net earned premiums	159,000,000	[3]	222,000,000	[3]	570,000,000	[3]	635,000,000	[3]
Loss and LAE:
Direct	25,000,000		108,000,000		18,000,000		545,000,000
Assumed	35,000,000		(4,000,000)		70,000,000		13,000,000
Ceded	(5,000,000)		(18,000,000)		(19,000,000)		(112,000,000)
Loss and LAE	$ 55,000,000		$ 86,000,000		$ 69,000,000		$ 446,000,000

[1] Negative assumed premiums written were due to changes in expected Debt Service schedules.

[2] Positive ceded premiums written were due to commutations and changes in expected Debt Service schedules.

[3] Excludes $14 million and $17 million for Third Quarter 2013 and 2012, respectively, and $47 million and $50 million for the Nine Months 2013 and 2012, respectively, related to consolidated FG VIEs.