Financial Guaranty Insurance - Deferred Acquisition Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Beginning of period	$ 121	$ 124	$ 116
DAC adjustments related to Radian Asset Acquisition on April 1, 2015	1	0	0
Costs deferred during the period:
Commissions on assumed and ceded business	(1)	7	9
Premium taxes	2	3	4
Compensation and other acquisition costs	11	10	8
Total costs deferred	12	20	21
Costs amortized during the period	20	(23)	(13)
End of period	$ 114	$ 121	$ 124