Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Assets
Cash and cash equivalents	$ 600	$ 1,258
Gross deferred tax asset	986
Deferred income taxes, net	950
Investments held-to-maturity, at amortized cost (fair value $2,780 and $2,651)	2,787	2,801
Total assets	16,024	16,953
Liabilities:
Total liabilities	12,216	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	3,118	3,115
Retained earnings	2,665	2,289
Accumulated other comprehensive income (loss), net of tax of $20 and $54	56	(86)
Treasury stock, at cost--86,924,313 and 85,562,546 shares	(2,333)	(2,318)
Total shareholders' equity of MBIA Inc.	3,787	3,278
Preferred stock of subsidiary and noncontrolling interest	21	21
Total equity	3,808	3,299
Total liabilities and equity	16,024	16,953
Non Variable Interest Entity [Member]
Assets
Fixed-maturity securities held as available-for-sale, at fair value (amortized cost $5,235 and $5,064) Investments held as available-for-sale, at fair value (amortized cost $0 and $136)	5,340	4,987
Investments carried at fair value	244	204
Investments pledged as collateral, at fair value (amortized cost $370 and $483)	341	424
Short-term investments held as available-for-sale, at fair value (amortized cost $1,218 and $1,203)	1,219	1,204
Other investments (includes investments at fair value of $13 and $11)	17	16
Total investments	7,161	6,835
Cash and cash equivalents	534	1,161
Premiums receivable	975	1,051
Deferred acquisition costs	243	260
Insurance loss recoverable	624	694
Assets held for sale	29	29
Gross deferred tax asset	986
Deferred income taxes, net		1,109
Other assets	243	222
Liabilities:
Unearned premium revenue	2,251	2,441
Loss and loss adjustment expense reserves	554	641
Investment agreements	660	700
Medium-term notes (includes financial instruments carried at fair value of $217 and $203)	1,286	1,427
Long-term debt	1,755	1,702
Derivative liabilities	449	1,152
Other liabilities	313	294
Variable Interest Entity Primary Beneficiary [Member]
Assets
Fixed-maturity securities held as available-for-sale, at fair value (amortized cost $5,235 and $5,064) Investments held as available-for-sale, at fair value (amortized cost $0 and $136)	0	136
Investments carried at fair value	474	587
Cash	66	97
Investments held-to-maturity, at amortized cost (fair value $2,780 and $2,651)	2,787	2,801
Loans receivable at fair value	1,539	1,612
Loan repurchase commitments	363	359
Liabilities:
Derivative liabilities	11	11
Variable interest entity notes (includes financial instruments carried at fair value of $2,150 and $2,356)	$ 4,937	$ 5,286