Common And Preferred Stock (Detail) (USD $)	0 Months Ended	1 Months Ended	12 Months Ended		12 Months Ended				12 Months Ended
	Feb. 01, 2007	Aug. 12, 2011 Directors	Dec. 31, 2012 M	Dec. 31, 2011	Dec. 31, 2012 MBIA Insurance Corporation [Member]	Dec. 31, 2012 Preferred Stock [Member]	Dec. 31, 2012 Preferred Stock [Member] MBIA Insurance Corporation [Member]	Dec. 31, 2012 2007 Repurchase Authorization [Member]	Dec. 31, 2012 Warrants [Member]	Dec. 31, 2012 B Warrants [Member]	Dec. 31, 2012 B2 Warrants [Member]	Dec. 31, 2012 Long-Term Incentive Plan [Member]	Dec. 31, 2011 Long-Term Incentive Plan [Member]	Dec. 31, 2012 Unaffiliated Investors [Member]
Class of Stock [Line Items]
Purchase of common stock									11,500,000	9,800,000	4,000,000
Exercise price of common stock									30.25	30.25	16.20
Fair value of warrants			$ 6,000,000	$ 38,000,000
Authorized repurchase of common stock, value	1,000,000,000
Repurchased under share repurchase program, shares			56,700,000			1,444
Repurchased under share repurchase program, cost			2,275,000,000	2,276,000,000				977,000,000
Repurchased under share repurchase program, average price per share			$ 17.24
Remaining amount available under repurchase program			23,000,000
Shares purchased for settling awards under long-term incentive plans												8,784	102,578
Preferred stock issued, shares			0	0	2,759
Preferred stock outstanding, shares			0	0										1,315
Preferred stock, carrying value issued and outstanding					$ 28,000,000									$ 12,000,000
Repurchased under share repurchase program, average price per share							10,900
Face value of preferred stock					10.90%
Preferred stock, par value			$ 1	$ 1		$ 1,000
Preferred stock liquidation preference						$ 100,000
Dividend rate on preferred stock determined rate						LIBOR plus 200 basis points
Period of non payment of dividends on preferred stock, months			18
Number of new directors elected		2