Consolidated Statements Of Operations - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenues:
Net realized investment gains (losses)				$ (10)	$ (24)
Net gains (losses) on financial instruments at fair value and foreign exchange		$ 11	$ 9	(1)	26
Net gains (losses) on extinguishment of debt		1	4	1	4
Fees and reimbursements		0	4	0	4
Total revenues		28	40	30	80
Expenses:
Losses and loss adjustment		28	20	35	69
Interest		53	43	104	84
Total expenses		106	76	191	189
Income (loss) from continuing operations before income taxes		(78)	(36)	(161)	(109)
Provision (benefit) for income taxes		0	0	0	0
Income (loss) from continuing operations		(78)	(36)	(161)	(109)
Income (loss) from discontinued operations, net of income taxes		3	0	0	0
Net income (loss)		(75)	(36)	(161)	(109)
Less: Net income from discontinued operations attributable to noncontrolling interest		(1)	0	6	0
Net income (loss) attributable to MBIA Inc.		$ (74)	$ (36)	$ (167)	$ (109)
Net income (loss) per common share attributable to MBIA Inc. - basic and diluted
Continuing operations - basic		$ (1.52)	$ (0.72)	$ (3.38)	$ (2.2)
Continuing operations - diluted		(1.52)	(0.72)	(3.38)	(2.2)
Discontinued operations - basic		0.06	0	(0.13)	0
Discontinued operations - diluted		0.06	0	(0.13)	0
Net income (loss) per common share attributable to MBIA Inc. - basic		(1.46)	(0.72)	(3.51)	(2.2)
Net income (loss) per common share attributable to MBIA Inc. - diluted		$ (1.46)	$ (0.72)	$ (3.51)	$ (2.2)
Weighted average number of common shares outstanding:
Basic	[1]	49,040,489	49,826,695	49,490,701	49,729,610
Diluted	[1]	49,040,489	49,826,695	49,490,701	49,729,610
Non Variable Interest Entity [Member]
Revenues:
Scheduled premiums earned		$ 8	$ 10	$ 18	$ 21
Refunding premiums earned		0	1	0	5
Premiums earned (net of ceded premiums of $0, $0, $0 and $1)		8	11	18	26
Net investment income		38	25	63	43
Net realized investment gains (losses)		(7)	(21)	(10)	(24)
Net gains (losses) on financial instruments at fair value and foreign exchange		11	9	(1)	26
Other net realized gains (losses)		1	(16)	1	(19)
Expenses:
Losses and loss adjustment		28	20	35	69
Amortization of deferred acquisition costs		1	1	2	3
Operating		20	11	42	30
Interest		53	43	104	84
Variable Interest Entity Primary Beneficiary [Member]
Revenues:
Net gains (losses) on financial instruments at fair value and foreign exchange		(21)	24	(24)	20
Other net realized gains (losses)		(3)	0	(18)	0
Expenses:
Operating		$ 4	$ 1	$ 8	$ 3

[1] Includes approximately 1 million of participating securities that met the service condition and were eligible to receive nonforfeitable dividends or dividend equivalents for the three and six months ended June 30, 2023 and 2022.