Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 627	$ 782
Insurance loss recoverable	527	533
Assets held for sale	22	802
Net deferred tax asset	1,000	1,000
Investments held-to-maturity, at amortized cost (fair value $2,635 and $2,632)	2,742	2,757
Total assets	15,915	16,284
Liabilities:
Liabilities held for sale	0	772
Total liabilities	11,975	12,334
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--281,670,699 and 281,352,782	282	281
Additional paid-in capital	3,124	3,128
Retained earnings	2,927	2,858
Accumulated other comprehensive income (loss), net of tax of $4 and $7	22	21
Treasury stock, at cost--98,097,072 and 89,409,887 shares	(2,436)	(2,359)
Total shareholders' equity of MBIA Inc.	3,919	3,929
Preferred stock of subsidiary and noncontrolling interest	21	21
Total equity	3,940	3,950
Total liabilities and equity	15,915	16,284
Non Variable Interest Entity [Member]
Assets
Fixed-maturity securities held as available-for-sale, at fair value (amortized cost $5,155 and $5,036)	5,279	5,129
Investments carried at fair value	217	207
Investments pledged as collateral, at fair value (amortized cost $217 and $441)	183	408
Short-term investments held as available-for-sale, at fair value (amortized cost $1,114 and $1,069)	1,117	1,069
Other investments (includes investments at fair value of $13 and $13)	17	17
Total investments	6,813	6,830
Cash and cash equivalents	596	729
Premiums receivable	848	875
Deferred acquisition costs	204	217
Insurance loss recoverable	527	533
Assets held for sale	22
Net deferred tax asset	969
Deferred income taxes, net		1,028
Other assets	232	229
Liabilities:
Unearned premium revenue	1,874	1,986
Loss and loss adjustment expense reserves	499	506
Investment agreements	538	547
Medium-term notes (includes financial instruments carried at fair value of $180 and $197)	1,108	1,201
Long-term debt	1,828	1,810
Derivative liabilities	391	437
Other liabilities	266	271
Variable Interest Entity Primary Beneficiary [Member]
Assets
Investments carried at fair value	1,061	421
Cash	31	53
Investments held-to-maturity, at amortized cost (fair value $2,635 and $2,632)	2,742	2,757
Loans receivable at fair value	1,480	1,431
Loan repurchase commitments	385	379
Derivative assets	5	0
Liabilities:
Derivative liabilities	76	0
Variable interest entity notes (includes financial instruments carried at fair value of $2,653 and $2,047)	$ 5,395	$ 4,804