Reinsurance and Other Monoline Exposures (Details 2) (USD $)									1 Months Ended					1 Months Ended
	Jun. 30, 2012		Jun. 30, 2012 AGM and AGC	Jun. 30, 2012 National Public Finance Guarantee Corporation	Jun. 30, 2012 American Overseas Reinsurance Company Limited		Jun. 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.	Jun. 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	Jun. 30, 2012 Syncora Guarantee Inc.		Jun. 30, 2012 Mitsui Sumitomo Insurance Co. Ltd.		Jun. 30, 2012 ACA Financial Guaranty Corp.		Jun. 30, 2012 Swiss Reinsurance Co.		Jun. 30, 2012 Ambac		Jun. 30, 2012 CIFG Assurance North America Inc.		Jun. 30, 2012 MBIA Inc.		Jun. 30, 2012 Financial Guaranty Insurance Co.		Jun. 30, 2012 Other
Exposure, Premium Receivable, and Loss and LAE by Reinsurer
Fixed maturity securities wrapped by monoline reinsurer				$ 713,900,000																				$ 538,500,000								$ 39,900,000
Ceded Par Outstanding	33,990,000,000	[1]			10,716,000,000	[1],[2]	8,995,000,000	[1]			5,441,000,000	[1]				4,082,000,000	[1]	2,294,000,000	[1]	843,000,000	[1]	458,000,000	[1]	85,000,000	[1]	65,000,000	[1]	0	[1]	0	[1]	1,011,000,000	[1]
Second-to-Pay Insured Par Outstanding	26,777,000,000				0	[2]	0				45,000,000					2,079,000,000		0		7,000,000		0		7,162,000,000		258,000,000		11,510,000,000		3,711,000,000		2,005,000,000
Assumed Par Outstanding	41,989,000,000				24,000,000	[2]	937,000,000				1,776,000,000					213,000,000		0		1,000,000		0		21,743,000,000		5,821,000,000		9,283,000,000		2,095,000,000		96,000,000
Ceded par outstanding related to insured credit derivatives	4,405,000,000
Assumed Premium Receivable, net of Commissions	92,200,000				0		0				0					0		0				0		81,700,000		100,000		500,000		9,900,000		0
Ceded Premium Payable, net of Commissions	(145,600,000)				(12,200,000)		(25,200,000)				(18,800,000)					(38,000,000)		(4,600,000)				(3,400,000)		0		0		0		0		(43,400,000)
Assumed Expected Loss and LAE	(143,300,000)				0		0				0					500,000		0				0		(100,300,000)		0		(16,400,000)		(27,100,000)		0
Ceded Expected Loss and LAE	192,100,000				23,200,000		88,100,000				28,000,000					600,000		28,300,000				22,700,000		0		1,200,000		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													1,900,000
Payment receivable in connection with reinsurance													22,000,000
Premiums paid during the period	21,800,000
Remaining insurance premium payable	$ 21,800,000

[1] Includes $4,405 million in ceded par outstanding related to insured credit derivatives.

[2] Formerly RAM Reinsurance Company Ltd.