Insurance in Force (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2014
Guarantor Obligations [Line Items]
Transactions guaranteed by MBIA on behalf of affiliated companies	$ 1,900		$ 2,200
Derivative liabilities	66		88
Amount available under these letters of credit and trust arrangements	29
Aggregate amount of insurance in force ceded to reinsurers	7,600		9,500
Aggregate amount of insured par outstanding ceded to reinsurers	4,162	[1]	5,300
Recoveries received on claims for financial guarantee policies under reinsurance contracts	(12)
Ceding commissions from reinsurance	1		$ 1	$ 2
Salvage payments for reinsurance				$ 5
U S Public Finance Insurance [Member]
Guarantor Obligations [Line Items]
Aggregate amount of insured par outstanding ceded to reinsurers	3,400
Structured Finance And International Insurance [Member]
Guarantor Obligations [Line Items]
Aggregate amount of insured par outstanding ceded to reinsurers	804
MBIA UK [Member]
Guarantor Obligations [Line Items]
Guarantee Obligations Maximum Exposure	18,600
Aggregate amount of insurance in force ceded to reinsurers	267
Aggregate amount of insured par outstanding ceded to reinsurers	170
Guarantees Of Derivative Contracts [Member]
Guarantor Obligations [Line Items]
Guarantee Obligations Maximum Exposure	$ 1,000
Minimum [Member]
Guarantor Obligations [Line Items]
Insurance in force, expected maturity range, years	1 year
Guarantees of derivative contracts, maturity range, minimum (Years)	1 year
Minimum [Member] | Investment Agreement Contracts and MTNs [Member]
Guarantor Obligations [Line Items]
Future guarantee payments, maturity range, (years)	1 year
Maximum [Member]
Guarantor Obligations [Line Items]
Insurance in force, expected maturity range, years	41 years
Guarantees of derivative contracts, maturity range, maximum (Years)	40 years
Maximum [Member] | Investment Agreement Contracts and MTNs [Member]
Guarantor Obligations [Line Items]
Future guarantee payments, maturity range, (years)	21 years

[1] Includes $170 million in ceded par outstanding related to MBIA UK.