Consolidated Variable Interest Entities - Consolidated FG VIE's By Type of Collateral (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Variable Interest Entity [Line Items]
Financial guaranty variable interest entities' assets with recourse, at fair value	$ 1,239	$ 1,449
Financial guaranty variable interest entities’ liabilities with recourse, at fair value	1,277	1,790
Financial guaranty variable interest entities' assets without recourse, at fair value	163	1,116
Financial guaranty variable interest entities’ liabilities without recourse, at fair value	142	1,081
Financial guaranty variable interest entities’ assets, at fair value	1,402	2,565
Financial guaranty variable interest entities’ liabilities, at fair value	1,419	2,871
Other Insurance Product Line [Member]
Variable Interest Entity [Line Items]
Financial guaranty variable interest entities' assets with recourse, at fair value	369	359
Financial guaranty variable interest entities’ liabilities with recourse, at fair value	369	359
United States [Member] | First Lien [Member] | RMBS [Member]
Variable Interest Entity [Line Items]
Financial guaranty variable interest entities' assets with recourse, at fair value	632	630
Financial guaranty variable interest entities’ liabilities with recourse, at fair value	581	791
United States [Member] | Second Lien [Member] | RMBS [Member]
Variable Interest Entity [Line Items]
Financial guaranty variable interest entities' assets with recourse, at fair value	238	460
Financial guaranty variable interest entities’ liabilities with recourse, at fair value	$ 327	$ 640