Reinsurance and Other Monoline Exposures (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Dec. 31, 2012	Mar. 31, 2013 AG Re	Feb. 14, 2013 AG Re	Mar. 31, 2013 AGC
Exposure, Premium Receivable, and Loss and LAE by Reinsurer
Fair market value of company's pledged securities	$ 709				$ 660	$ 323	$ 27	$ 143
Additional ceding commission						8
Commutation gains (losses)			83
Premiums Written:
Direct	19		62
Assumed	(2)	[1]	26	[1]
Ceded	(2)	[2]	87	[2]
Net	15		175
Commutations	0		106
Increase (Decrease) in Net Par Due to Commutations	0		19,073
Premiums Earned:
Direct	267		206
Assumed	13		14
Ceded	(32)		(26)
Net earned premiums	248	[3]	194	[3]
Loss and LAE:
Direct	(27)		304
Assumed	(14)		17
Ceded	(7)		(79)
Loss and LAE	$ (48)		$ 242

[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 $18 million and $17 million for First Quarter 2013 and 2012, respectively, related to consolidated FG VIEs.