Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Assets
Cash and cash equivalents	$ 606	$ 1,258
Deferred income taxes, net	1,000
Investments held-to-maturity, at amortized cost (fair value $2,730 and $2,651)	2,772	2,801
Total assets	16,201	16,953
Liabilities:
Total liabilities	12,299	13,654
Commitments and contingencies (See Note 13)
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--281,359,451 and 277,812,430	281	278
Additional paid-in capital	3,123	3,115
Retained earnings	2,838	2,289
Accumulated other comprehensive income (loss), net of tax of $17 and $54	(14)	(86)
Treasury stock, at cost--88,167,959 and 85,562,546 shares	(2,347)	(2,318)
Total shareholders' equity of MBIA Inc.	3,881	3,278
Preferred stock of subsidiary and noncontrolling interest	21	21
Total equity	3,902	3,299
Total liabilities and equity	16,201	16,953
Non Variable Interest Entity [Member]
Assets
Fixed-maturity securities held as available-for-sale, at fair value (amortized cost $5,274 and $5,064) Investments held as available-for-sale, at fair value (amortized cost $0 and $136)	5,305	4,987
Investments carried at fair value	238	204
Investments pledged as collateral, at fair value (amortized cost $363 and $483)	330	424
Short-term investments held as available-for-sale, at fair value (amortized cost $1,147 and $1,203)	1,148	1,204
Other investments (includes investments at fair value of $13 and $11)	17	16
Total investments	7,038	6,835
Cash and cash equivalents	550	1,161
Premiums receivable	936	1,051
Deferred acquisition costs	229	260
Insurance loss recoverable	575	694
Assets held for sale	29	29
Gross deferred tax asset	1,047
Deferred income taxes, net		1,109
Other assets	231	222
Liabilities:
Unearned premium revenue	2,125	2,441
Loss and loss adjustment expense reserves	517	641
Investment agreements	659	700
Medium-term notes (includes financial instruments carried at fair value of $202 and $203)	1,229	1,427
Long-term debt	1,784	1,702
Derivative liabilities	428	1,152
Other liabilities	276	294
Variable Interest Entity Primary Beneficiary [Member]
Assets
Fixed-maturity securities held as available-for-sale, at fair value (amortized cost $5,274 and $5,064) Investments held as available-for-sale, at fair value (amortized cost $0 and $136)	0	136
Investments carried at fair value	471	587
Cash	56	97
Investments held-to-maturity, at amortized cost (fair value $2,730 and $2,651)	2,772	2,801
Loans receivable at fair value	1,902	1,612
Loan repurchase commitments	365	359
Liabilities:
Derivative liabilities	7	11
Variable interest entity notes (includes financial instruments carried at fair value of $2,463 and $2,356)	5,235	5,286
Payable for loans purchased	$ 39	$ 0