Schedule II (Condensed Balance Sheets) (Detail) - USD ($) $ / shares in Units, $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Assets [Abstract]
Fixed-maturity securities held as available-for-sale, at fair value (amortized cost $131 and $463)	$ 1,557	$ 1,931
Total assets	2,606	3,375
Liabilities:
Total liabilities	4,253	4,251
Equity:
Preferred stock, par value $1 per share; authorized shares—10,000,000; issued and outstanding—none	0	0
Common stock, par value $1 per share; authorized shares--400,000,000; issued shares--283,186,115 and 283,186,115	283	283
Additional paid-in capital	2,515	2,925
Retained earnings (deficit)	(1,144)	(653)
Accumulated other comprehensive income (loss), net of tax	(139)	(283)	$ 100	$ 115
Treasury stock, at cost--232,323,184 and 228,333,444 shares	(3,172)	(3,154)
Total shareholders' equity of MBIA Inc.	(1,657)	(882)
Total liabilities and equity	2,606	$ 3,375
Fixed-maturity securities held as available-for-sale, amortized cost	$ 1,688
Preferred stock, par value	$ 1	$ 1
Preferred stock, authorized shares	10,000,000	10,000,000
Preferred stock, issued	0	0
Preferred stock, outstanding	0	0
Common stock, par value	$ 1	$ 1
Common stock, authorized shares	400,000,000	400,000,000
Common stock, issued shares	283,186,115	283,186,115
Treasury stock, shares	232,323,184	228,333,444
Parent Company [Member]
Assets [Abstract]
Fixed-maturity securities held as available-for-sale, at fair value (amortized cost $131 and $463)	$ 127	$ 431
Short-term investments held as available-for-sale, at fair value (amortized cost $480 and $95)	480	95
Total investments	607	526
Cash and cash equivalents	33	16	$ 15	$ 26
Other assets	26	9
Total assets	666	551
Liabilities:
Investment agreements	221	233
Long-term debt	278	278
Affiliate loans payable	533	535
Derivative liabilities	1	48
Accumulated loss of wholly-owned subsidiaries	1,290	333
Other liabilities	0	6
Total liabilities	2,323	1,433
Equity:
Preferred stock, par value $1 per share; authorized shares—10,000,000; issued and outstanding—none	0	0
Common stock, par value $1 per share; authorized shares--400,000,000; issued shares--283,186,115 and 283,186,115	283	283
Additional paid-in capital	2,515	2,925
Retained earnings (deficit)	(1,144)	(653)
Accumulated other comprehensive income (loss), net of tax	(139)	(283)
Treasury stock, at cost--232,323,184 and 228,333,444 shares	(3,172)	(3,154)
Total shareholders' equity of MBIA Inc.	(1,657)	(882)
Total liabilities and equity	666	551
Fixed-maturity securities held as available-for-sale, amortized cost	131	463
Short-term investments, amortized cost	$ 480	$ 95
Preferred stock, par value	$ 1	$ 1
Preferred stock, authorized shares	10,000,000	10,000,000
Preferred stock, issued	0	0
Preferred stock, outstanding	0	0
Common stock, par value	$ 1	$ 1
Common stock, authorized shares	400,000,000	400,000,000
Common stock, issued shares	283,186,115	283,186,115
Treasury stock, shares	232,323,184	228,333,444