Schedule II (Condensed Balance Sheets) (Detail) - USD ($) $ / shares in Units, $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets [Abstract]
Cash and cash equivalents	$ 83	$ 280	$ 146	$ 187
Total assets	7,284	8,107
Liabilities:
Long-term debt	2,228	2,249
Total liabilities	6,445	6,975
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—283,433,401 and 283,625,689	283	284
Additional paid-in capital	2,999	3,025
Retained earnings	607	966
Accumulated other comprehensive income (loss), net of tax	(2)	(156)	(19)	(128)
Treasury stock, at cost—203,157,759 and 193,803,976 shares	(3,061)	(3,000)
Total shareholders' equity of MBIA Inc.	826	1,119
Total liabilities and equity	$ 7,284	$ 8,107
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	283,433,401	283,625,689
Treasury stock, shares	204,000,108	193,803,976
Parent Company [Member]
Assets [Abstract]
Fixed-maturity securities held as available-for-sale, at fair value (amortized cost $610 and $815)	$ 674	$ 839
Investments carried at fair value	1	7
Investments pledged as collateral, at fair value (amortized cost $19 and $49)	11	46
Short-term investments held as available-for-sale, at fair value (amortized cost $167 and $83)	167	83
Total investments	853	975
Cash and cash equivalents	11	40	$ 10	$ 13
Investment in wholly-owned subsidiaries	1,456	1,876
Other assets	123	130
Total assets	2,443	3,021
Liabilities:
Investment agreements	274	276
Long-term debt	427	577
Affiliate loans payable	658	675
Income taxes payable	60	138
Derivative liabilities	133	157
Other liabilities	65	79
Total liabilities	1,617	1,902
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—283,433,401 and 283,625,689	283	284
Additional paid-in capital	2,999	3,025
Retained earnings	607	966
Accumulated other comprehensive income (loss), net of tax	(2)	(156)
Treasury stock, at cost—203,157,759 and 193,803,976 shares	(3,061)	(3,000)
Total shareholders' equity of MBIA Inc.	826	1,119
Total liabilities and equity	2,443	3,021
Fixed-maturity securities held as available-for-sale, amortized cost	610	815
Investments pledged as collateral, amortized cost	19	49
Short-term investments, amortized cost	$ 167	$ 83
Preferred stock, par value	$ 1	$ 1
Preferred stock, authorized shares	10,000,000	10,000,000
Common stock, par value	$ 1	$ 1
Common stock, authorized shares	400,000,000	400,000,000
Common stock, issued shares	283,433,401	283,625,689
Treasury stock, shares	204,000,108	193,803,976