Insurance In Force (Schedule Of Insurance In Force By Type Of Bond, Excluding Transactions Guaranteed By MBIA Corp. On Behalf Of Various Investment Management Services Affiliated Companies) (Detail) (USD $) In Billions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Insurance in Force	$ 554.3		$ 679.1
% of Insurance in Force	100.00%		100.00%
U S [Member]
Insurance in Force	492.7		604.3
% of Insurance in Force	88.90%		89.00%
Non-United States [Member]
Insurance in Force	61.6		74.8
% of Insurance in Force	11.10%		11.00%
Global Public Finance [Member]
Insurance in Force	491.7		580.5
% of Insurance in Force	88.70%		85.50%
Global Public Finance [Member] | U S [Member]
Insurance in Force	445.7		530.9
% of Insurance in Force	80.40%		78.20%
Global Public Finance [Member] | Non-United States [Member]
Insurance in Force	46.0		49.6
% of Insurance in Force	8.30%		7.30%
Global Structured Finance [Member]
Insurance in Force	62.6		98.6
% of Insurance in Force	11.30%		14.50%
General Obligation [Member] | Global Public Finance [Member] | U S [Member]
Insurance in Force	153.5		187.5
% of Insurance in Force	27.70%		27.60%
General Obligation - Lease [Member] | Global Public Finance [Member] | U S [Member]
Insurance in Force	34.1		41.7
% of Insurance in Force	6.20%		6.10%
Municipal Utilities [Member] | Global Public Finance [Member] | U S [Member]
Insurance in Force	78.0		97.1
% of Insurance in Force	14.10%		14.30%
Tax-Backed [Member] | Global Public Finance [Member] | U S [Member]
Insurance in Force	66.1		71.9
% of Insurance in Force	11.90%		10.60%
Tax-Backed [Member] | Global Public Finance [Member] | Non-United States [Member]
Insurance in Force	0.2		0.2
% of Insurance in Force	0.00%		0.00%
Transportation [Member] | Global Public Finance [Member] | U S [Member]
Insurance in Force	46.2		52.1
% of Insurance in Force	8.30%		7.70%
Transportation [Member] | Global Public Finance [Member] | Non-United States [Member]
Insurance in Force	12.2		14.2
% of Insurance in Force	2.20%		2.10%
Higher Education [Member] | Global Public Finance [Member] | U S [Member]
Insurance in Force	24.1		30.3
% of Insurance in Force	4.30%		4.50%
Health Care [Member] | Global Public Finance [Member] | U S [Member]
Insurance in Force	9.5		12.1
% of Insurance in Force	1.70%		1.80%
Health Care [Member] | Global Public Finance [Member] | Non-United States [Member]
Insurance in Force	0		0.1
% of Insurance in Force	0.00%		0.00%
Military Housing [Member] | Global Public Finance [Member] | U S [Member]
Insurance in Force	19.2		19.0
% of Insurance in Force	3.50%		2.80%
Investor-Owned Utilities [Member] | Global Public Finance [Member] | U S [Member]
Insurance in Force	7.2	[1]	8.7	[1]
% of Insurance in Force	1.30%	[1]	1.30%	[1]
Municipal Housing [Member] | Global Public Finance [Member] | U S [Member]
Insurance in Force	4.8		7.2
% of Insurance in Force	0.90%		1.00%
Student Loans [Member] | Global Public Finance [Member] | U S [Member]
Insurance in Force	0.6		0.7
% of Insurance in Force	0.10%		0.10%
Other Public Finance [Member] | Global Public Finance [Member] | U S [Member]
Insurance in Force	2.4	[2]	2.6	[2]
% of Insurance in Force	0.40%	[2]	0.40%	[2]
International Utilities [Member] | Global Public Finance [Member] | Non-United States [Member]
Insurance in Force	15.9		16.2
% of Insurance in Force	2.90%		2.40%
Sovereign Related And Sub-Sovereign [Member] | Global Public Finance [Member] | Non-United States [Member]
Insurance in Force	17.3	[3]	18.4	[3]
% of Insurance in Force	3.10%	[3]	2.70%	[3]
Local Governments [Member] | Global Public Finance [Member] | Non-United States [Member]
Insurance in Force	0.4	[4]	0.5	[4]
% of Insurance in Force	0.10%	[4]	0.10%	[4]
Collateralized Debt Obligations [Member] | Global Structured Finance [Member]
Insurance in Force	31.7	[5]	57.6	[5]
% of Insurance in Force	5.70%	[5]	8.50%	[5]
Residential Mortgage Backed Securities [Member] | Global Structured Finance [Member]
Insurance in Force	12.4		17.1
% of Insurance in Force	2.20%		2.50%
Commercial Mortgage Backed Securities [Member] | Global Structured Finance [Member]
Insurance in Force	1.6		3.8
% of Insurance in Force	0.30%		0.60%
Consumer Asset-Backed, Student Loans [Member] | Global Structured Finance [Member]
Insurance in Force	1.1		1.2
% of Insurance in Force	0.20%		0.20%
Consumer Asset-Backed, Manufactured Housing [Member] | Global Structured Finance [Member]
Insurance in Force	1.7		2.0
% of Insurance in Force	0.30%		0.30%
Other Consumer Asset-Backed [Member] | Global Structured Finance [Member]
Insurance in Force	0		0.1
% of Insurance in Force	0.00%		0.00%
Corporate Asset-Backed, Operating Assets, Aircraft Portfolio Lease Securitizations [Member]
Insurance in Force	1.8		2.5
% of Insurance in Force	0.30%		0.40%
Corporate Asset-Backed, Operating Assets, Secured Airline Equipment Securitization (EETC) [Member]
Insurance in Force	1.8		2.4
% of Insurance in Force	0.30%		0.30%
Corporate Asset-Backed, Operating Assets, Other Operating Assets [Member]
Insurance in Force	0.2		0.5
% of Insurance in Force	0.10%		0.10%
Corporate Asset-Backed, Structured Insurance Securitizations [Member] | Global Structured Finance [Member]
Insurance in Force	5.5		6.1
% of Insurance in Force	1.00%		0.90%
Corporate Asset-Backed, Franchise Assets [Member] | Global Structured Finance [Member]
Insurance in Force	0.8		0.9
% of Insurance in Force	0.20%		0.10%
Corporate Asset-Backed, Future Flow [Member] | Global Structured Finance [Member]
Insurance in Force	0.1		0.2
% of Insurance in Force	0.00%		0.00%
Other Corporate Asset-Backed [Member] | Global Structured Finance [Member]
Insurance in Force	$ 3.9		$ 4.2
% of Insurance in Force	0.70%		0.60%

[1] Includes investor owned utilities, industrial development and pollution control revenue bonds.

[2] Includes certain non-profit enterprises and stadium related financing.

[3] Includes regions, departments or their equivalent in each jurisdiction as well as sovereign owned entities that are supported by a sovereign state, region or department.

[4] Includes municipal owned entities backed by sponsoring local government.

[5] Includes transactions (represented by structured pools of primarily investment grade corporate credit risks or CRE assets) that do not include typical CDO structuring characteristics, such as tranched credit risk, cash flow waterfalls, or interest and over-collateralization coverage tests.