Reinsurance and Other Monoline Exposures - Effect of Reinsurance on Statement of Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Premiums Written:
Direct	$ 23	$ 17	$ 52	$ 48
Assumed	(1)	0	2	(1)
Ceded	2	2	2	(22)
Net	24	19	56	25
Premiums Earned:
Direct	224	147	372	287
Assumed	12	9	22	20
Ceded	(17)	(20)	(33)	(39)
Net earned premiums	219	136	361	268
Loss and LAE:
Direct	186	70	212	104
Assumed	19	9	12	15
Ceded	(17)	(22)	(18)	(21)
Loss and LAE	$ 188	$ 57	$ 206	$ 98