Consolidated Statement Of Changes In Shareholders' Equity (USD $) In Millions, except Share data	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]	Total
Beginning Balance at Dec. 31, 2011	$ 275	$ 3,072	$ 805	$ (176)	$ (2,276)	$ 1,700	$ 23	$ 1,723
Beginning Balance (in shares) at Dec. 31, 2011	274,896,162				(81,752,966)		1,315
Net income			10			10		10
Other comprehensive income (loss)				150		150		150
Share-based compensation net of tax of $5 (in Shares)	592,752				2,839
Share-based compensation net of tax of $5		(2)				(2)		(2)
Ending balance at Mar. 31, 2012	$ 275	$ 3,070	$ 815	$ (26)	$ (2,276)	$ 1,858	$ 23	$ 1,881
Ending Balance (in shares) at Mar. 31, 2012	275,488,914				(81,750,127)		1,315