Financial Guaranty Contracts Accounted for as Credit Derivatives - Net Change in Fair Value of Credit Derivatives Gain (Loss) and Net Par and Accelerations of Credit Derivative Revenues from Termination of CDS Contracts (Details) (USD $)	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Realized gains on credit derivatives	$ 20,000,000	[1]	$ 28,000,000	[1]
Net credit derivative losses (paid and payable) recovered and recoverable	(1,000,000)		(10,000,000)
Realized gains (losses) and other settlements on credit derivatives	19,000,000		18,000,000
Net change in unrealized gains (losses) on credit derivatives	(230,000,000)	[2],[3]	(610,000,000)	[2],[3]
Net change in fair value of credit derivatives	(211,000,000)		(592,000,000)
Net par of terminated CDS contracts	1,100,000,000		1,100,000,000
Accelerations of credit derivative revenues	$ 200,000		$ 1,000,000

[1] Includes accelerations due to terminations of CDS contracts of $0.2 million and $1 million related to net par of $1.1 billion and $1.1 billion for First Quarter 2014 and First Quarter 2013, respectively.

[2] Except for net estimated credit impairments (i.e., net expected loss to be paid as discussed in Note 5), the unrealized gains and losses on credit derivatives are expected to reduce to zero as the exposure approaches its maturity date. With considerable volatility continuing in the market, unrealized gains (losses) on credit derivatives may fluctuate significantly in future periods.

[3] “Other” includes all other U.S. and international asset classes, such as commercial receivables, international infrastructure, international RMBS securities, and pooled infrastructure securities.