Financial Guaranty Insurance - Reconciliation of Net Expected Loss to be Paid and Expensed (Details) - USD ($) $ in Millions		Mar. 31, 2016		Dec. 31, 2015		Mar. 31, 2015	Dec. 31, 2014
Guarantor Obligations [Line Items]
Net expected loss to be paid after recoveries for R&W		$ 1,337	[1]	$ 1,391	[1]	$ 1,154	$ 1,169
Contra-paid, net	[2],[3]	14		6
Loss and LAE reserve - financial guaranty insurance contracts, net of reinsurance	[4]	(1,040)		(998)
Other recoveries		3		3
Net expected loss to be expensed (present value)		389
Variable Interest Entity, Primary Beneficiary [Member]
Guarantor Obligations [Line Items]
Net expected loss to be expensed (present value)		74
Financial Guarantee Insurance And Other Product Line [Member]
Guarantor Obligations [Line Items]
Net expected loss to be paid after recoveries for R&W	[5]	1,210
Contra-paid, net		14
Salvage and subrogation recoverable, net of reinsurance		201
Loss and LAE reserve - financial guaranty insurance contracts, net of reinsurance		(1,038)
Other recoveries		2
Net expected loss to be expensed (present value)	[6]	389
Financial Guarantee Insurance And Other Product Line [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Guarantor Obligations [Line Items]
Loss and LAE reserve - financial guaranty insurance contracts, net of reinsurance		71		74
Financial Guarantee Insurance And Other Product Line [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Guarantor Obligations [Line Items]
Loss and LAE reserve - financial guaranty insurance contracts, net of reinsurance		$ (1,111)		$ (1,072)

[1] Includes expected LAE to be paid of $9 million as of March 31, 2016 and $12 million as of December 31, 2015.

[2] Excludes $105 million and $110 million of deferred premium revenue, and $29 million and $30 million of contra-paid related to FG VIEs as of March 31, 2016 and December 31, 2015, respectively.

[3] See "Financial Guaranty Insurance Losses– Insurance Contracts' Loss Information" below for an explanation of "contra-paid".

[4] See “Components of Net Reserves (Salvage)” table for loss and LAE reserve and salvage and subrogation recoverable components.

[5] See "Net Expected Loss to be Paid (Recovered) by Accounting Model" table in Note 5, Expected Loss to be Paid.

[6] Excludes $74 million as of March 31, 2016, related to consolidated FG VIEs.