Common and Preferred Stock (Narrative) (Detail) (USD $)	12 Months Ended			0 Months Ended		12 Months Ended	0 Months Ended	12 Months Ended	83 Months Ended		12 Months Ended								0 Months Ended
	Dec. 31, 2013	Dec. 31, 2011	Dec. 31, 2012	May 06, 2013 Blue Ridge [Member]	Aug. 05, 2013 Warburg Pincus [Member]	Dec. 31, 2013 Preferred Stock [Member] MBIA Insurance Corporation [Member]	Feb. 01, 2007 2007 Repurchase Authorization [Member]	Dec. 31, 2013 2007 Repurchase Authorization [Member]	Dec. 31, 2013 2007 Repurchase Authorization [Member]	Dec. 31, 2013 Unaffiliated Investors [Member] MBIA Insurance Corporation [Member]	Dec. 31, 2013 Long-Term Incentive Plan [Member]	Dec. 31, 2012 Long-Term Incentive Plan [Member]	Aug. 05, 2013 Warrant [Member] Warburg Pincus [Member]	Dec. 31, 2008 Warrant [Member] Warburg Pincus [Member]	Aug. 05, 2013 B Warrants [Member] Warburg Pincus [Member]	Dec. 31, 2008 B Warrants [Member] Warburg Pincus [Member]	Aug. 05, 2013 B2 Warrants [Member] Warburg Pincus [Member]	Dec. 31, 2008 B2 Warrants [Member] Warburg Pincus [Member]	Aug. 05, 2013 Grossup Warrant [Member] Warburg Pincus [Member]
Class of Stock [Line Items]
Warrants outstanding				9,940,000	1,910,000								11,800,000	11,500,000	10,100,000	9,800,000	4,004,945	4,000,000	1,910,000
Warrant exercise price				9.59	9.59								29.44	30.25	29.44	30.25	16.18	16.20	9.59
Warrant Term				5 years															5 years
Fair value of warrants	$ 59,000,000		$ 6,000,000
Authorized repurchase of common stock, value							1,000,000,000
Treasury stock shares acquired									56,700,000		392,056	8,784
Treasury stock value acquired cost method	7,000,000	50,000,000							977,000,000
Shares repurchased under share repurchase program, average price per share						$ 10,900			$ 17.24
Remaining amount available under repurchase program								23,000,000
Preferred stock shares issued	0		0			2,759
Preferred stock repurchased during period shares						1,444
Preferred stock shares outstanding	0		0							1,315
Preferred stock, carrying value issued and outstanding						$ 28,000,000
Face value of repurchased preferred stock						10.90%
Preferred Stock Par Or Stated Value Per Share	$ 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