Reinsurance and Other Monoline Exposures (Details 2) (USD $)										1 Months Ended					1 Months Ended
	Sep. 30, 2012		Sep. 30, 2012 AGM and AGC	Jan. 12, 2012 AGM and AGC	Sep. 30, 2012 National Public Finance Guarantee Corporation	Sep. 30, 2012 American Overseas Reinsurance Company Limited		Sep. 30, 2012 Tokio Marine & Nichido Fire Insurance Co., Ltd.		Feb. 29, 2012 Tokio Marine & Nichido Fire Insurance Co., Ltd. Public finance	Jan. 31, 2012 Radian Asset Assurance Inc.	Sep. 30, 2012 Radian Asset Assurance Inc.		Jan. 24, 2012 Radian Asset Assurance Inc.	Jan. 31, 2012 Radian Asset Assurance Inc. Public finance	Jan. 31, 2012 Radian Asset Assurance Inc. Structured finance	Sep. 30, 2012 Syncora Guarantee Inc.		Sep. 30, 2012 Mitsui Sumitomo Insurance Co. Ltd.		Sep. 30, 2012 ACA Financial Guaranty Corp.		Sep. 30, 2012 Swiss Reinsurance Co.		Sep. 30, 2012 Ambac		Sep. 30, 2012 CIFG Assurance North America Inc.		Sep. 30, 2012 MBIA Inc.		Sep. 30, 2012 Financial Guaranty Insurance Co.		Sep. 30, 2012 Other
Exposure, Premium Receivable, and Loss and LAE by Reinsurer
Fixed maturity securities wrapped by monoline reinsurer					$ 664,000,000																				$ 537,000,000								$ 36,000,000
Ceded Par Outstanding	33,190,000,000	[1]				10,309,000,000	[1],[2]	8,748,000,000	[1]			5,364,000,000	[1]				4,092,000,000	[1]	2,256,000,000	[1]	829,000,000	[1]	434,000,000	[1]	85,000,000	[1]	65,000,000	[1]	0	[1]	0	[1]	1,008,000,000	[1]
Second-to-Pay Insured Par Outstanding	26,396,000,000					0	[2]	0				44,000,000					2,043,000,000		0		6,000,000		0		7,151,000,000		255,000,000		11,497,000,000		3,336,000,000		2,064,000,000
Assumed Par Outstanding	40,329,000,000					24,000,000	[2]	937,000,000				1,474,000,000					165,000,000		0		1,000,000		0		21,231,000,000		5,583,000,000		8,798,000,000		2,020,000,000		96,000,000
Ceded par outstanding related to insured credit derivatives	4,198,000,000
Assumed Premium Receivable, net of Commissions	90,000,000					0		0				0					0		0				0		81,000,000		0		0		9,000,000		0
Ceded Premium Payable, net of Commissions	(138,000,000)					(12,000,000)		(23,000,000)				(18,000,000)					(37,000,000)		(5,000,000)				(3,000,000)		0		0		0		0		(40,000,000)
Assumed Expected Loss and LAE	(136,000,000)					0		0				0					1,000,000		0				0		(85,000,000)		0		(22,000,000)		(30,000,000)		0
Ceded Expected Loss and LAE	54,000,000					12,000,000		35,000,000				(4,000,000)					0		8,000,000				1,000,000		0		2,000,000		0		0		0
Minimum net losses required for attachment of excess of loss reinsurance facility			2,000,000,000
Amount of losses covered under the facility			600,000,000
Amount of losses which the reinsurers will assume on pro rata basis				435,000,000
Remaining amount of losses covered under the facility			165,000,000
Amount agreed to be reassumed										6,200,000,000	12,900,000,000
Approximate amount of insurance risk agreed to be assumed											1,800,000,000
Payment receivable for re-assumption of ceded risk														86,000,000
Percentage of obligations insured															96.00%	4.00%
Incremental present value from future installment premiums														2,000,000
Payment receivable in connection with reinsurance														22,000,000
Premiums paid during the period	22,000,000
Remaining insurance premium payable	$ 22,000,000

[1] Includes $4,198 million in ceded par outstanding related to insured credit derivatives.

[2] Formerly RAM Reinsurance Company Ltd.