Consolidated Statement Of Changes In Shareholders' Equity (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
ASC 944-20 transition adjustment, tax			$ 27
ASC 320-10 transition adjustment, tax			30
Consolidated variable interest entities, tax		23
Deconsolidated variable interest entities, tax		2
Change in unrealized gains and losses on investments, tax	119	112	526
Change in fair value of derivative instruments, tax	3	(7)	46
Change in foreign currency translation, tax	(1)	2	4
Total Shareholders' Equity Of MBIA Inc. [Member]
Change in unrealized gains and losses on investments, tax	119	112	526
Portion of other-than-temporary impairment losses recognized in other comprehensive loss, tax	3	4	50
Change in fair value of derivative instruments, tax	3	7	46
Change in foreign currency translation, tax	1	2	4
Share-based compensation, tax	$ 4	$ 3	$ 5

Tax benefit associated with any equity-based compensation plan other than an employee stock ownership plan (ESOP). The tax benefit results from the deduction by the entity on its tax return for an award of stock that exceeds the cumulative compensation cost for common stock or preferred stock recognized for financial reporting. Includes any resulting tax benefit that exceeds the previously recognized deferred tax asset (excess tax benefits).

+ References+ Details

Total tax effect of the change in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. The change includes an entity's share of an equity investee's increase or decrease in deferred hedging gains or losses. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References+ Details

- Definition

Tax effect of the adjustment that results from the process of translating subsidiary financial statements and foreign equity investments into functional currency of the reporting entity. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

+ References+ Details

- Definition

Tax effect on gross appreciation or the gross loss in value of the total of unsold securities during the period being reported on.

+ References+ Details