Debt (Long-Term Debt) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
Debt Instrument [Line Items]
Long-term debt, gross	$ 592		$ 732
Less unamortized discount	0		1
Subtotal	592		731
Surplus notes outstanding	940	[1]	940	[1]
Total	1,702		1,732
6.400% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	266	[2]	269	[2]
Long-term debt, interest rate	6.40%
Long-term debt, maturity year	2022
Initial Callable date	Aug. 15, 2006
7.000% Debentures Due 2025 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	56		56
Long-term debt, interest rate	7.00%
Long-term debt, maturity year	2025
7.150% Debentures Due 2027 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	100		100
Long-term debt, interest rate	7.15%
Long-term debt, maturity year	2027
6.625% Debentures Due 2028 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	141		141
Long-term debt, interest rate	6.625%
Long-term debt, maturity year	2028
5.700% Senior Notes Due 2034 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	21	[3]	157	[3]
Long-term debt, interest rate	5.70%
Long-term debt, maturity year	2034
14% Surplus Notes Due 2033 [Member]
Debt Instrument [Line Items]
Accrued interest	170		61
Long-term debt, interest rate	14.00%
Long-term debt, maturity year	2033
Callable date for fifth anniversary of initial callable date	2018-01-15
Callable date for subsequent fifth anniversary of initial callable date	2023-01-15
Latest callable date before maturity	Jan. 15, 2028
Long-term debt, maturity date	Jan. 15, 2033
MBIA Inc Senior Notes [Member]
Debt Instrument [Line Items]
Accrued interest	$ 8		$ 9

[1] Callable on or after January 15, 2018 and every fifth anniversary thereafter at 100.00.

[2] Callable on or after August 15, 2006 at 100.00.

[3] Callable anytime at the greater of 100.00 or the present value of the remaining scheduled payments of principal and interest.