Consolidated Balance Sheets (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Assets
Cash and cash equivalents	$ 1,239	$ 1,130
Total assets	29,370	32,279
Liabilities:
Total liabilities	26,995	29,433
Commitments and contingencies (See Note 13)
Equity:
Preferred stock, par value $1 per share; authorized shares-10,000,000; issued and outstanding-none
Common stock, par value $1 per share; authorized shares-400,000,000; issued shares-274,913,262 and 274,719,578	275	275
Additional paid-in capital	3,070	3,064
Retained earnings	1,431	2,124
Accumulated other comprehensive loss, net of deferred tax of $94 and $229	(148)	(406)
Treasury stock, at cost-81,755,455 and 74,973,978 shares	(2,276)	(2,225)
Total shareholders' equity of MBIA Inc.	2,352	2,832
Preferred stock of subsidiary and noncontrolling interest	23	14
Total equity	2,375	2,846
Total liabilities and equity	29,370	32,279
Non Variable Interest Entities [Member]
Assets
Fixed-maturity securities held as available-for-sale, at fair value	7,818	9,092
Fixed-maturity securities at fair value	286	25
Investments pledged as collateral, at fair value (amortized cost $666 and $548)	591	552
Short-term investments held as available-for-sale, at fair value (amortized cost $1,486 and $2,073)	1,487	2,070
Other investments (includes investments at fair value of $139 and $186)	151	188
Total	10,333	11,927
Cash and cash equivalents	659	366
Accrued investment income	91	95
Premiums receivable	1,399	1,589
Deferred acquisition costs	364	412
Prepaid reinsurance premiums	91	97
Insurance loss recoverable	2,770	2,531
Reinsurance recoverable on paid and unpaid losses	18	15
Goodwill	31	31
Property and equipment, at cost (less accumulated depreciation of $138 and $135)	69	71
Receivable for investments sold	46	8
Derivative assets	2	4
Current income taxes		41
Deferred income taxes, net	1,298	908
Other assets	55	46
Liabilities:
Unearned premium revenue	3,648	4,145
Loss and loss adjustment expense reserves	932	1,129
Reinsurance premiums payable	64	71
Investment agreements	1,635	2,005
Medium-term notes (includes financial instruments carried at fair value $128 and $116)	1,636	1,740
Securities sold under agreements to repurchase	387	471
Short-term debt		65
Long-term debt	1,841	1,851
Current income taxes	37
Deferred fee revenue	8	10
Payable for investments purchased	54	2
Derivative liabilities	5,266	4,617
Other liabilities	205	272
Variable Interest Entity, Primary Beneficiary [Member]
Assets
Fixed-maturity securities held as available-for-sale, at fair value	532	339
Fixed-maturity securities at fair value	3,276	5,241
Derivative assets	713	699
Other assets	1	38
Cash	580	764
Investments held-to-maturity, at amortized cost (fair value $3,492 and $3,760)	3,886	4,039
Loans receivable at fair value	2,218	2,183
Loan repurchase commitments	938	835
Total assets	12,100	14,100
Liabilities:
Long-term debt	360	360
Derivative liabilities	1,888	2,104
Other liabilities	1	1
Variable interest entity notes (includes financial instruments carried at fair value $5,123 and $6,680)	9,033	10,590
Total liabilities	$ 11,300	$ 13,100