Financial Guaranty Insurance Premiums - Components of Unearned Premium Reserve (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Financial Guaranty Insurance Premiums [Line Items]
Deferred premium revenue, gross	$ 4,440		$ 4,652
Deferred premium revenue, ceded	451		470
Deferred premium revenue, net	3,989	[1]	4,182	[1]
Unearned premium reserve	4,391		4,595
Prepaid Reinsurance Premiums	440		452
Unearned Premiums, Net	3,951	[1]	4,143	[1]
Total net unearned premium reserve related to FG VIE	132		187
Contra-paid related to FG and VIEs	47		55
Financial guaranty insurance
Financial Guaranty Insurance Premiums [Line Items]
Deferred premium revenue, gross	4,435		4,647
Deferred premium revenue, ceded	451		470
Deferred premium revenue, net	3,984	[1]	4,177	[1]
Contra-paid, gross	(49)		(57)
Contra-paid, ceded	(11)		(18)
Contra-paid, net	(38)	[1]	(39)	[1]
Other
Financial Guaranty Insurance Premiums [Line Items]
Unearned premium reserve	5		5
Prepaid Reinsurance Premiums	0		0
Unearned Premiums, Net	$ 5	[1]	$ 5	[1]

[1] Excludes $132 million and $187 million of deferred premium revenue, and $47 million and $55 million of contra-paid related to FG VIEs as of June 30, 2014 and December 31, 2013, respectively.