Financial Guaranty Insurance Losses (Details 6) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Jun. 30, 2013 risk		Dec. 31, 2012 risk
Outstanding exposure:
Reserves (salvage)	$ 210	[1]	$ 133	[1]
Effect of Consolidating FG VIEs
Outstanding exposure:
Present value of expected cash flows	(31)
Financial guaranty
Outstanding exposure:
Present value of expected cash flows	(530)		(451)
Reserves (salvage)	189		106
Financial guaranty | BIG 1 | Gross
Financial Guaranty Insurance BIG Transaction Loss Summary
Number of risks	144		153
Remaining weighted-average contract period (in years)	11 years 3 months 18 days		11 years
Outstanding exposure:
Principal	7,135		8,533
Interest	4,153		4,357
Total	11,288		12,890
Expected cash outflows (inflows)	1,199		1,582
Potential recoveries	(1,247)		(1,629)
Subtotal	(48)		(47)
Discount	1		(1)
Present value of expected cash flows	(47)		(48)
Deferred premium revenue	168		111
Reserves (salvage)	(86)		(103)
Financial guaranty | BIG 1 | Ceded
Financial Guaranty Insurance BIG Transaction Loss Summary
Number of risks	(47)		(57)
Remaining weighted-average contract period (in years)	7 years 9 months 18 days		9 years 3 months 18 days
Outstanding exposure:
Principal	(1,159)		(1,484)
Interest	(463)		(585)
Total	(1,622)		(2,069)
Expected cash outflows (inflows)	(435)		(677)
Potential recoveries	441		653
Subtotal	6		(24)
Discount	1		9
Present value of expected cash flows	7		(15)
Deferred premium revenue	(36)		(24)
Reserves (salvage)	11		(4)
Financial guaranty | BIG 2 | Gross
Financial Guaranty Insurance BIG Transaction Loss Summary
Number of risks	83		76
Remaining weighted-average contract period (in years)	10 years 2 months 12 days		11 years 6 months 0 days
Outstanding exposure:
Principal	3,703		2,741
Interest	1,849		1,813
Total	5,552		4,554
Expected cash outflows (inflows)	916		863
Potential recoveries	(516)		(509)
Subtotal	400		354
Discount	(118)		(107)
Present value of expected cash flows	282		247
Deferred premium revenue	221		227
Reserves (salvage)	125		102
Financial guaranty | BIG 2 | Ceded
Financial Guaranty Insurance BIG Transaction Loss Summary
Number of risks	(27)		(22)
Remaining weighted-average contract period (in years)	13 years		15 years 3 months 18 days
Outstanding exposure:
Principal	(394)		(135)
Interest	(179)		(131)
Total	(573)		(266)
Expected cash outflows (inflows)	(104)		(58)
Potential recoveries	29		18
Subtotal	(75)		(40)
Discount	26		14
Present value of expected cash flows	(49)		(26)
Deferred premium revenue	(30)		(15)
Reserves (salvage)	(32)		(18)
Financial guaranty | BIG 3 | Gross
Financial Guaranty Insurance BIG Transaction Loss Summary
Number of risks	148		142
Remaining weighted-average contract period (in years)	9 years		8 years 6 months
Outstanding exposure:
Principal	7,065		7,568
Interest	2,387		2,269
Total	9,452		9,837
Expected cash outflows (inflows)	2,937		3,052
Potential recoveries	(2,181)		(2,639)
Subtotal	756		413
Discount	(371)		(202)
Present value of expected cash flows	385		211
Deferred premium revenue	647		757
Reserves (salvage)	156		(35)
Financial guaranty | BIG 3 | Ceded
Financial Guaranty Insurance BIG Transaction Loss Summary
Number of risks	(52)	[2]	(51)	[2]
Remaining weighted-average contract period (in years)	6 years 7 months 6 days		5 years 9 months 18 days
Outstanding exposure:
Principal	(516)		(540)
Interest	(151)		(137)
Total	(667)	[3]	(677)	[3]
Expected cash outflows (inflows)	(141)		(156)
Potential recoveries	119	[4]	142	[4]
Subtotal	(22)		(14)
Discount	5		0
Present value of expected cash flows	(17)		(14)
Deferred premium revenue	(80)		(90)
Reserves (salvage)	(1)	[5]	11	[5]
Financial guaranty | Below investment grade (BIG)
Financial Guaranty Insurance BIG Transaction Loss Summary
Number of risks	375	[2]	371	[2]
Remaining weighted-average contract period (in years)	10 years 4 months 24 days		10 years 2 months 12 days
Outstanding exposure:
Principal	15,834		16,683
Interest	7,596		7,586
Total	23,430	[3]	24,269	[3]
Expected cash outflows (inflows)	3,667		3,868
Potential recoveries	(2,726)	[4]	(3,166)	[4]
Subtotal	941		702
Discount	(411)		(251)
Present value of expected cash flows	530		451
Deferred premium revenue	688		715
Reserves (salvage)	189	[5]	106	[5]
Financial guaranty | Below investment grade (BIG) | Total BIG, Net
Financial Guaranty Insurance BIG Transaction Loss Summary
Number of risks	375	[2]	371	[2]
Remaining weighted-average contract period (in years)	10 years 4 months 24 days		10 years 2 months 12 days
Outstanding exposure:
Principal	15,834		16,683
Interest	7,596		7,586
Total	23,430	[3]	24,269	[3]
Expected cash outflows (inflows)	4,372		4,606
Potential recoveries	(3,355)	[4]	(3,964)	[4]
Subtotal	1,017		642
Discount	(456)		(287)
Present value of expected cash flows	561		355
Deferred premium revenue	890		966
Reserves (salvage)	173	[5]	(47)	[5]
Financial guaranty | Below investment grade (BIG) | Effect of Consolidating FG VIEs
Financial Guaranty Insurance BIG Transaction Loss Summary
Number of risks	0	[2]	0	[2]
Outstanding exposure:
Principal	0		0
Interest	0		0
Total	0	[3]	0	[3]
Expected cash outflows (inflows)	(705)		(738)
Potential recoveries	629	[4]	798	[4]
Subtotal	(76)		60
Discount	45		36
Present value of expected cash flows	(31)		96
Deferred premium revenue	(202)		(251)
Reserves (salvage)	$ 16	[5]	$ 153	[5]

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

[2] A risk represents the aggregate of the financial guaranty policies that share the same revenue source for purposes of making Debt Service payments. The ceded number of risks represents the number of risks for which the Company ceded a portion of its exposure.

[3] Includes BIG amounts related to FG VIEs.

[4] Includes estimated future recoveries for breaches of R&W as well as excess spread, and draws on HELOCs.

[5] See table “Components of net reserves (salvage).”