Consolidated Statements Of Changes In Shareholders' Equity (USD $) In Millions, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Total Shareholders' Equity Of MBIA Inc. [Member]	Preferred Stock Of Subsidiary And Noncontrolling Interest [Member]
Beginning Balance at Dec. 31, 2009	$ 2,607	$ 275	$ 3,058	$ 2,393	$ (941)	$ (2,195)	$ 2,590	$ 17
Beginning Balance (in shares) at Dec. 31, 2009		274,826,872				(70,159,024)		1,677
ASU 2009-17 transition adjustment:
Consolidated variable interest entities, net of tax	(55)			(319)	264		(55)
Deconsolidated variable interest entities, net of tax	82			(3)	85		82
Total ASU 2009-17 transition adjustment	27			(322)	349		27
Net income	53			53			53
Other comprehensive income	186				186		186
Share-based compensation, net of tax (in shares)		(107,294)				(78,654)
Share-based compensation, net of tax	7		6			1	7
Treasury shares acquired under share repurchase program (in shares)						(4,736,300)
Treasury shares acquired under share repurchase program	(31)					(31)	(31)
Preferred shares of subsidiary acquired (in shares)								(251)
Preferred shares of subsidiary acquired	(3)							(3)
Ending Balance at Dec. 31, 2010	2,846	275	3,064	2,124	(406)	(2,225)	2,832	14
Ending Balance (in shares) at Dec. 31, 2010		274,719,578				(74,973,978)		1,426
ASU 2009-17 transition adjustment:
Net income	(1,319)			(1,319)			(1,319)
Other comprehensive income	230				230		230
Share-based compensation, net of tax (in shares)		176,584				(237,912)
Share-based compensation, net of tax	7		8			(1)	7
Treasury shares acquired under share repurchase program (in shares)						(6,541,076)
Treasury shares acquired under share repurchase program	(50)					(50)	(50)
Preferred shares of subsidiary acquired (in shares)								(111)
Preferred shares of subsidiary acquired	(2)							(2)
Change in noncontrolling interest in subsidiary	11							11
Ending Balance at Dec. 31, 2011	1,723	275	3,072	805	(176)	(2,276)	1,700	23
Ending Balance (in shares) at Dec. 31, 2011		274,896,162				(81,752,966)		1,315
ASU 2009-17 transition adjustment:
Net income	1,234			1,234			1,234
Other comprehensive income	232				232		232
Share-based compensation, net of tax (in shares)		2,508,877				19,436
Share-based compensation, net of tax	7	2	4			1	7
Change in noncontrolling interest in subsidiary	(2)							(2)
Ending Balance at Dec. 31, 2012	$ 3,194	$ 277	$ 3,076	$ 2,039	$ 56	$ (2,275)	$ 3,173	$ 21
Ending Balance (in shares) at Dec. 31, 2012		277,405,039				(81,733,530)		1,315