Reinsurance and Other Monoline Exposures - Effect of Reinsurance on Statement of Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013		Dec. 31, 2013
Exposure, Premium Receivable, and Loss and LAE by Reinsurer
Fair market value of company's pledged securities	$ 472				$ 472				$ 677
Increase (Decrease) in Net Par Due to Commutations					856
Premiums Written:
Direct	17		1		48		20
Assumed	0	[1]	21	[1]	(1)	[1]	19	[1]
Ceded	2	[2]	1	[2]	(22)	[2]	(1)	[2]
Net	19		23		25		38
Premiums Earned:
Direct	147		187		287		454
Assumed	9		1		20		14
Ceded	(20)		(25)		(39)		(57)
Net earned premiums	136		163		268		411
Loss and LAE:
Direct	70		20		104		(7)
Assumed	9		49		15		35
Ceded	(22)		(7)		(21)		(14)
Loss and LAE	57		62		98		14
AG Re
Exposure, Premium Receivable, and Loss and LAE by Reinsurer
Fair market value of company's pledged securities	286				286
AGC
Exposure, Premium Receivable, and Loss and LAE by Reinsurer
Fair market value of company's pledged securities	$ 54				$ 54

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

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