Consolidated Statements Of Changes In Shareholders' Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (deficit) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Total Shareholders' Equity Of MBIA Inc. [Member]	Preferred Stock [Member]	Preferred Stock And Non Controlling Interest Held For Sale [Member]
Total equity balance at Dec. 31, 2020			$ 2,962	$ (13)	$ 115	$ (3,211)	$ 136		$ 13
Balance (in treasury stock shares) at Dec. 31, 2020						(229,508,967)
Net income (loss)	$ (290)			(290)
Other comprehensive income (loss)	(25)				(25)
Other						$ 35
Others (in shares)						728,928
Period change			(26)				(306)		0
Total equity balance at Sep. 30, 2021	(157)	$ 283	2,936	(303)	90	$ (3,176)	(170)		13
Balance (in common stock shares) at Sep. 30, 2021		283,186,115
Balance (in treasury stock shares) at Sep. 30, 2021						(228,780,039)
Balance (in preferred stock shares) at Sep. 30, 2021								1,315
Total equity balance at Jun. 30, 2021			2,934	(180)	103	$ (3,176)	(36)		13
Balance (in treasury stock shares) at Jun. 30, 2021						(228,780,540)
Net income (loss)	(123)			(123)
Other comprehensive income (loss)	(13)				(13)
Other						$ 0
Others (in shares)						501
Period change			2				(134)		0
Total equity balance at Sep. 30, 2021	(157)	$ 283	2,936	(303)	90	$ (3,176)	(170)		13
Balance (in common stock shares) at Sep. 30, 2021		283,186,115
Balance (in treasury stock shares) at Sep. 30, 2021						(228,780,039)
Balance (in preferred stock shares) at Sep. 30, 2021								1,315
Total equity balance at Dec. 31, 2021	$ (300)		2,931	(458)	100	$ (3,169)	(313)		13
Balance (in treasury stock shares) at Dec. 31, 2021	(228,630,003)					(228,630,003)
Net income (loss)	$ (143)			(143)
Other comprehensive income (loss)	(414)				(414)
Other						$ 17
Others (in shares)						344,097
Period change			(10)				(550)		1
Total equity balance at Sep. 30, 2022	$ (849)	$ 283	2,921	(601)	(314)	$ (3,152)	(863)		14
Balance (in common stock shares) at Sep. 30, 2022	283,186,115	283,186,115
Balance (in treasury stock shares) at Sep. 30, 2022	(228,285,906)					(228,285,906)
Balance (in preferred stock shares) at Sep. 30, 2022	0							1,315
Total equity balance at Jun. 30, 2022			2,919	(567)	(231)	$ (3,152)	(748)		13
Balance (in treasury stock shares) at Jun. 30, 2022						(228,286,399)
Net income (loss)	$ (34)			(34)
Other comprehensive income (loss)	(83)				(83)
Other						$ 0
Others (in shares)						493
Period change			2				(115)		1
Total equity balance at Sep. 30, 2022	$ (849)	$ 283	$ 2,921	$ (601)	$ (314)	$ (3,152)	$ (863)		$ 14
Balance (in common stock shares) at Sep. 30, 2022	283,186,115	283,186,115
Balance (in treasury stock shares) at Sep. 30, 2022	(228,285,906)					(228,285,906)
Balance (in preferred stock shares) at Sep. 30, 2022	0							1,315