Reinsurance and Other Monoline Exposures (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012		Dec. 31, 2012	Jun. 30, 2013 AG Re	Feb. 14, 2013 AG Re	Jun. 30, 2013 AGC
Exposure, Premium Receivable, and Loss and LAE by Reinsurer
Fair market value of company's pledged securities	$ 680				$ 680				$ 660	$ 310	$ 27	$ 135
Additional ceding commission										8
Commutations							106
Increase (Decrease) in Net Par Due to Commutations							19,073
Commutation gains (losses)							83
Premiums Written:
Direct	1		45		20		107
Assumed	21	[1]	(14)	[1]	19	[1]	12	[1]
Ceded	1	[2]	1	[2]	(1)	[2]	88	[2]
Net	23		32		38		207
Premiums Earned:
Direct	187		245		454		451
Assumed	1		12		14		26
Ceded	(25)		(38)		(57)		(64)
Net earned premiums	163	[3]	219	[3]	411	[3]	413	[3]
Loss and LAE:
Direct	20		87		(7)		391
Assumed	49		46		35		63
Ceded	(7)		(15)		(14)		(94)
Loss and LAE	$ 62		$ 118		$ 14		$ 360

[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 $15 million and $16 million for Second Quarter 2013 and 2012, respectively, and $33 million and $33 million for the Six Months 2013 and 2012, respectively, related to consolidated FG VIEs.