Assured Guaranty (AGO) 10-Q 8 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	7-May-15
Document And Entity Information [Abstract]
Entity Registrant Name	ASSURED GUARANTY LTD
Entity Central Index Key	1273813
Document Type	10-Q
Document Period End Date	31-Mar-15
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		150,902,096
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Investment portfolio:
Fixed-maturity securities, available-for-sale, at fair value (amortized cost of $9,310 and $9,972)	$9,833	$10,491
Short-term investments, at fair value	349	767
Other invested assets	132	126
Total investment portfolio	10,314	11,384
Cash	885	75
Premiums receivable, net of commissions payable	700	729
Ceded unearned premium reserve	365	381
Deferred acquisition costs	120	121
Reinsurance recoverable on unpaid losses	77	78
Salvage and subrogation recoverable	128	151
Credit derivative assets	77	68
Deferred tax asset, net	218	260
Financial guaranty variable interest entities’ assets, at fair value	1,499	1,402
Other assets	294	276
Total assets	14,677	14,925
Liabilities and shareholders’ equity
Unearned premium reserve	4,127	4,261
Loss and loss adjustment expense reserve	787	799
Reinsurance balances payable, net	74	107
Long-term debt	1,304	1,303
Credit derivative liabilities	859	963
Current income tax payable	0	5
Financial guaranty variable interest entities’ liabilities with recourse, at fair value	1,278	1,277
Financial guaranty variable interest entities’ liabilities without recourse, at fair value	145	142
Other liabilities	317	310
Total liabilities	8,891	9,167
Commitments and contingencies (See Note 14)
Common stock ($0.01 par value, 500,000,000 shares authorized; 152,835,331 and 158,306,661 shares issued and outstanding)	2	2
Additional paid-in capital	1,733	1,887
Retained earnings	3,676	3,494
Accumulated other comprehensive income, net of tax of $149 and $159	370	370
Deferred equity compensation (320,193 and 320,193 shares)	5	5
Total shareholders’ equity	5,786	5,758
Total liabilities and shareholders’ equity	$14,677	$14,925

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Fixed maturity securities, available-for-sale, at fair value	$9,310	$9,972
Common stock par value (per share)	$0.01	$0.01
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	152,835,331	158,306,661
Common stock, shares outstanding	152,835,331	158,306,661
Accumulated other comprehensive income, tax provision	$149	$159
Deferred equity compensation, shares	320,193	320,193

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues
Net earned premiums	$142	$132
Net investment income	101	103
Net realized investment gains (losses):
Other-than-temporary impairment losses	-5	-3
Less: portion of other-than-temporary impairment loss recognized in other comprehensive income	2	2
Net impairment loss	-7	-5
Other net realized investment gains (losses)	23	7
Net realized investment gains (losses)	16	2
Net change in fair value of credit derivatives:
Realized gains (losses) and other settlements	21	19
Net unrealized gains (losses)	103	-230
Net change in fair value of credit derivatives	124	-211
Fair value gains (losses) on committed capital securities	2	-9
Fair value gains (losses) on financial guaranty variable interest entities	-7	157
Other income (loss)	-9	21
Total revenues	369	195
Expenses
Loss and loss adjustment expenses	18	41
Amortization of deferred acquisition costs	4	5
Interest expense	25	20
Other operating expenses	56	60
Total expenses	103	126
Income (loss) before income taxes	266	69
Provision (benefit) for income taxes
Current	13	21
Deferred	52	6
Total provision (benefit) for income taxes	65	27
Net income (loss)	$201	$42
Earnings per share:
Basic (in dollars per share)	$1.29	$0.23
Diluted (in dollars per share)	$1.28	$0.23
Dividends (in dollars per share)	$0.12	$0.11

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$201	$42
Unrealized holding gains (losses) arising during the period on:
Investments with no other-than-temporary impairment, net of tax provision (benefit) of $1 and $41	18	94
Investments with other-than-temporary impairment, net of tax provision (benefit) of $(2) and $3	-2	8
Unrealized holding gains (losses) arising during the period, net of tax	16	102
Less: reclassification adjustment for gains (losses) included in net income (loss), net of tax provision (benefit) of $6 and $(1)	10	-2
Change in net unrealized gains on investments	6	104
Other, net of tax provision	-6	0
Other comprehensive income (loss)	0	104
Comprehensive income (loss)	$201	$146

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Investments with no other-than-temporary impairment, tax provision (benefit)	$1	$41
Investments with other-than-temporary impairment, tax provision (benefit)	-2	3
Reclassification adjustment for gains (losses) included in net income (loss), tax provision (benefit)	$6	($1)

Consolidated_Statement_of_Shar

Consolidated Statement of Shareholders' Equity (USD $)	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income	Deferred Equity Compensation
In Millions, except Share data, unless otherwise specified
Beginning balance at Dec. 31, 2014	$5,758	$2	$1,887	$3,494	$370	$5
Beginning balance (in shares) at Dec. 31, 2014		158,306,661
Increase (Decrease) in Shareholders' Equity
Net Income	201			201
Dividends ($0.12 per share)	-19			-19
Common stock repurchases (in shares)		-5,860,291
Common stock repurchases	-152		-152
Share-based compensation and other (in shares)		388,961
Share-based compensation and other	-2		-2
Other comprehensive income	0
Ending balance at Mar. 31, 2015	$5,786	$2	$1,733	$3,676	$370	$5
Ending balance (in shares) at Mar. 31, 2015		152,835,331

Consolidated_Statement_of_Shar1

Consolidated Statement of Shareholders' Equity (Parenthetical) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Statement of Stockholders' Equity [Abstract]
Dividends, per share (in dollars per share)	$0.12	$0.11

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Cash Flows [Abstract]
Net cash flows provided by (used in) operating activities	$23	$101
Fixed-maturity securities:
Purchases	-448	-517
Sales	841	155
Maturities	155	148
Net sales (purchases) of short-term investments	420	184
Net proceeds from paydowns on financial guaranty variable interest entities’ assets	30	286
Other	3	19
Net cash flows provided by (used in) investing activities	1,001	275
Financing activities
Dividends paid	-19	-20
Repurchases of common stock	-152	-35
Share activity under option and incentive plans	-5	0
Net paydowns of financial guaranty variable interest entities’ liabilities	-39	-281
Repayment of long-term debt	-1	-6
Other	4	0
Net cash flows provided by (used in) financing activities	-212	-342
Effect of foreign exchange rate changes	-2	1
Increase (decrease) in cash	810	35
Cash at beginning of period	75	184
Cash at end of period	885	219
Supplemental cash flow information
Income taxes	17	37
Interest	$7	$8

Business_and_Basis_of_Presenta

Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Basis of Presentation	Business and Basis of Presentation
	Business
	Assured Guaranty Ltd. (“AGL” and, together with its subsidiaries, “Assured Guaranty” or the “Company”) is a Bermuda-based holding company that provides, through its operating subsidiaries, credit protection products to the United States (“U.S.”) and international public finance (including infrastructure) and structured finance markets. The Company applies its credit underwriting judgment, risk management skills and capital markets experience to offer financial guaranty insurance that protects holders of debt instruments and other monetary obligations from defaults in scheduled payments. If an obligor defaults on a scheduled payment due on an obligation, including a scheduled principal or interest payment (“Debt Service”), the Company is required under its unconditional and irrevocable financial guaranty to pay the amount of the shortfall to the holder of the obligation. The Company markets its financial guaranty insurance directly to issuers and underwriters of public finance and structured finance securities as well as to investors in such obligations. The Company guarantees obligations issued principally in the U.S. and the United Kingdom ("U.K."), and also guarantees obligations issued in other countries and regions, including Australia and Western Europe.
	In the past, the Company sold credit protection by issuing policies that guaranteed payment obligations under credit derivatives, primarily credit default swaps ("CDS"). Financial guaranty contracts accounted for as credit derivatives are generally structured such that the circumstances giving rise to the Company’s obligation to make loss payments are similar to those for financial guaranty insurance contracts. The Company’s credit derivative transactions are governed by International Swaps and Derivative Association, Inc. (“ISDA”) documentation. The Company has not entered into any new CDS in order to sell credit protection since the beginning of 2009, when regulatory guidelines were issued that limited the terms under which such protection could be sold. The capital and margin requirements applicable under the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) also contributed to the Company not entering into such new CDS since 2009. The Company actively pursues opportunities to terminate existing CDS, which have the effect of reducing future fair value volatility in income and/or reducing rating agency capital charges.
	Basis of Presentation
	The unaudited interim consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and, in the opinion of management, reflect all adjustments that are of a normal recurring nature, necessary for a fair statement of the financial condition, results of operations and cash flows of the Company and its consolidated financial guaranty variable interest entities (“FG VIEs”) for the periods presented. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. These unaudited interim consolidated financial statements are as of March 31, 2015 and cover the three-month period ended March 31, 2015 ("First Quarter 2015") and the three-month period ended March 31, 2014 ("First Quarter 2014"). Certain financial information that is normally included in annual financial statements prepared in accordance with GAAP, but is not required for interim reporting purposes, has been condensed or omitted. The year-end balance sheet data was derived from audited financial statements.
	The unaudited interim consolidated financial statements include the accounts of AGL, its direct and indirect subsidiaries (collectively, the “Subsidiaries”), and its consolidated FG VIEs. Intercompany accounts and transactions between and among all consolidated entities have been eliminated.
	These unaudited interim consolidated financial statements should be read in conjunction with the consolidated financial statements included in AGL’s Annual Report on Form 10-K for the year ended December 31, 2014, filed with the U.S. Securities and Exchange Commission (the “SEC”).
	The Company's principal insurance company subsidiaries are:
	•	Assured Guaranty Municipal Corp. ("AGM"), domiciled in New York;
	•	Municipal Assurance Corp. ("MAC"), domiciled in New York;
	•	Assured Guaranty Corp. ("AGC"), domiciled in Maryland;
	•	Assured Guaranty (Europe) Ltd. ("AGE"), organized in the United Kingdom; and
	•	Assured Guaranty Re Ltd. (“AG Re”), domiciled in Bermuda.
	On April 1, 2015, AGC completed the acquisition of all of the issued and outstanding capital stock of financial guaranty insurer Radian Asset Assurance Inc. (“Radian Asset”) in return for a payment to Radian Guaranty Inc. of $804.5 million made from AGC's available funds. Radian Asset was merged with and into AGC, with AGC as the surviving company of the merger. As of March 31, 2015, Radian Asset had approximately $1.3 billion of qualified statutory capital. The Radian Asset acquisition added $13.6 billion to net par outstanding on April 1, 2015, and is consistent with one of the Company's key business strategies of building a book of business through acquisitions. The Company is in the process of allocating the purchase price to the assets acquired and liabilities assumed and conforming accounting policies but has not yet completed the acquisition date balance sheet and pro forma financial statements. The Company intends to include this information in its Second Quarter 2015 Form 10-Q.
	The Company’s organizational structure includes various holding companies, two of which - Assured Guaranty US Holdings Inc. (“AGUS”) and Assured Guaranty Municipal Holdings Inc. (“AGMH”) - have public debt outstanding. See Note 15, Long-Term Debt and Credit Facilities.
	Future Application of Accounting Standards
	Consolidation
	In February 2015, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis, which is intended to improve certain areas of consolidation guidance for legal entities such as limited partnerships, limited liability companies, and securitization structures. The ASU will be effective on January 1, 2016. Early adoption is permitted, including adoption in an interim period. The Company does not expect that ASU 2015-02 will have any material effect on its Consolidated Financial Statements.
	Interest
	In April 2015, the FASB issued ASU No. 2015-03, Interest - Imputation of Interest (Topic 835-30): Simplifying the Presentation of Debt Issuance Costs, which requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The ASU will be effective on January 1, 2016 and should be applied retrospectively. The adoption of this ASU will require the Company to reclassify its debt issuance costs from other assets to long-term debt on the Consolidated Balance Sheet. As of March 31, 2015, the debt issuance costs were approximately $6 million.

Rating_Actions

Rating Actions	3 Months Ended
	Mar. 31, 2015
Rating Actions [Abstract]
Rating Actions	Rating Actions
	Rating Actions
	When a rating agency assigns a public rating to a financial obligation guaranteed by one of AGL’s insurance company subsidiaries, it generally awards that obligation the same rating it has assigned to the financial strength of the AGL subsidiary that provides the guaranty. Investors in products insured by AGL’s insurance company subsidiaries frequently rely on ratings published by the rating agencies because such ratings influence the trading value of securities and form the basis for many institutions’ investment guidelines as well as individuals’ bond purchase decisions. Therefore, the Company manages its business with the goal of achieving strong financial strength ratings. However, the methodologies and models used by rating agencies differ, presenting conflicting goals that may make it inefficient or impractical to reach the highest rating level. The methodologies and models are not fully transparent, contain subjective elements and data (such as assumptions about future market demand for the Company’s products) and change frequently. Ratings are subject to continuous review and revision or withdrawal at any time. If the financial strength ratings of one (or more) of the Company’s insurance subsidiaries were reduced below current levels, the Company expects it could have adverse effects on the impacted subsidiary's future business opportunities as well as the premiums the impacted subsidiary could charge for its insurance policies.
	In the last several years, Standard & Poor's Ratings Services ("S&P") and Moody's Investors Service, Inc. ("Moody's") have changed, multiple times, their financial strength ratings of AGL's insurance subsidiaries, or changed the outlook on such ratings. More recently, Kroll Bond Rating Agency ("KBRA") and A.M. Best Company, Inc. have assigned financial strength ratings to some of AGL's insurance subsidiaries. The rating agencies' most recent actions and proposals related to AGL's insurance subsidiaries are:
	•	On March 18, 2014, S&P upgraded the financial strength ratings of all of AGL's insurance subsidiaries to AA (stable outlook) from AA- (stable outlook); it affirmed such ratings in a credit analysis issued on July 2, 2014.
	•	On July 2, 2014, Moody's affirmed the ratings of AGL and its subsidiaries, but changed to negative the outlook of the financial strength ratings of AGC and its subsidiary Assured Guaranty (UK) Ltd. ("AGUK").
	•	On August 4, 2014, KBRA affirmed MAC's AA+ (stable outlook) financial strength rating.
	•	On November 13, 2014, KBRA assigned a financial strength rating of AA+ (stable outlook) to AGM.
	•	On January 20, 2015, Moody's adopted changes to its credit methodology for financial guaranty insurance companies, and on February 18, 2015 Moody's published a credit opinion maintaining its existing ratings of AGL and its subsidiaries under that new methodology.
	•	Effective April 8, 2015, at the Company's request, Moody’s withdrew the financial strength ratings it had assigned to Assured Guaranty Re Ltd. (AG Re) and Assured Guaranty Re Overseas Ltd. ("AGRO").
	•	On May 5, 2015, A.M. Best Company, Inc. assigned a financial strength rating of A+ (Stable) to AGRO.
	There can be no assurance that any of the rating agencies will not take negative action on their financial strength ratings of AGL's insurance subsidiaries in the future.
	For a discussion of the effects of rating actions on the Company, see the following:
	•	Note 6, Financial Guaranty Insurance Losses
	•	Note 8, Financial Guaranty Contracts Accounted for as Credit Derivatives
	•	Note 13, Reinsurance and Other Monoline Exposures
	•	Note 15, Long-Term Debt and Credit Facilities

Outstanding_Exposure

Outstanding Exposure	3 Months Ended
	Mar. 31, 2015
Outstanding Exposure Disclosure
Outstanding Exposure	Outstanding Exposure
	The Company’s financial guaranty contracts are written in either insurance or credit derivative form, but collectively are considered financial guaranty contracts. The Company seeks to limit its exposure to losses by underwriting obligations that are investment grade at inception, or in the case of restructurings of troubled credits, the Company may underwrite new issuances that one or more of the rating agencies may rate below-investment-grade ("BIG") as part of its loss mitigation strategy. The Company diversifies its insured portfolio across asset classes and, in the structured finance portfolio, requires rigorous subordination or collateralization requirements. Reinsurance is utilized in order to reduce net exposure to certain insured transactions.
	Public finance obligations insured by the Company consist primarily of general obligation bonds supported by the taxing powers of U.S. state or municipal governmental authorities, as well as tax-supported bonds, revenue bonds and other obligations supported by covenants from state or municipal governmental authorities or other municipal obligors to impose and collect fees and charges for public services or specific infrastructure projects. The Company also includes within public finance obligations those obligations backed by the cash flow from leases or other revenues from projects serving substantial public purposes, including utilities, toll roads, health care facilities and government office buildings.
	Structured finance obligations insured by the Company are generally issued by special purpose entities, including variable interest entities ("VIEs"), and backed by pools of assets having an ascertainable cash flow or market value or other specialized financial obligations. Some of these VIEs are consolidated as described in Note 9, Consolidated Variable Interest Entities. Unless otherwise specified, the outstanding par and Debt Service amounts presented in this note include outstanding exposures on VIEs whether or not they are consolidated.
	Surveillance Categories
	The Company segregates its insured portfolio into investment grade and BIG surveillance categories to facilitate the appropriate allocation of resources to monitoring and loss mitigation efforts and to aid in establishing the appropriate cycle for periodic review for each exposure. BIG exposures include all exposures with internal credit ratings below BBB-. The Company’s internal credit ratings are based on internal assessments of the likelihood of default and loss severity in the event of default. Internal credit ratings are expressed on a ratings scale similar to that used by the rating agencies and are generally reflective of an approach similar to that employed by the rating agencies, except that the Company's internal credit ratings focus on future performance, rather than lifetime performance.
	The Company monitors its investment grade credits to determine whether any need to be internally downgraded to BIG and refreshes its internal credit ratings on individual credits in quarterly, semi-annual or annual cycles based on the Company’s view of the credit’s quality, loss potential, volatility and sector. Ratings on credits in sectors identified as under the most stress or with the most potential volatility are reviewed every quarter. The Company’s credit ratings on assumed credits are based on the Company’s reviews of low-rated credits or credits in volatile sectors, unless such information is not available, in which case, the ceding company’s credit rating of the transactions are used. The Company models the performance of many of its structured finance transactions as part of its periodic internal credit rating review of them.
	Credits identified as BIG are subjected to further review to determine the probability of a loss. See Note 5, Expected Loss to be Paid, for additional information. Surveillance personnel then assign each BIG transaction to the appropriate BIG surveillance category based upon whether a future loss is expected and whether a claim has been paid. For surveillance purposes, the Company calculates present value using a constant discount rate of 4.5% or 5% depending on the insurance subsidiary. (Risk-free rates are used for calculating the expected loss for financial statement measurement purposes.)
	More extensive monitoring and intervention is employed for all BIG surveillance categories, with internal credit ratings reviewed quarterly. The Company expects “future losses” on a transaction when the Company believes there is at least a 50% chance that, on a present value basis, it will pay more claims in the future of that transaction than it will have reimbursed. The three BIG categories are:
	•	BIG Category 1: Below-investment-grade transactions showing sufficient deterioration to make future losses possible, but for which none are currently expected.
	•	BIG Category 2: Below-investment-grade transactions for which future losses are expected but for which no claims (other than liquidity claims which is a claim that the Company expects to be reimbursed within one year) have yet been paid.
	•	BIG Category 3: Below-investment-grade transactions for which future losses are expected and on which claims (other than liquidity claims) have been paid.
	Components of Outstanding Exposure
	Unless otherwise noted, ratings disclosed herein on the Company's insured portfolio reflect its internal ratings. The Company classifies those portions of risks benefiting from reimbursement obligations collateralized by eligible assets held in trust in acceptable reimbursement structures as the higher of 'AA' or their current internal rating.
	The Company purchases securities that it has insured, and for which it has expected losses to be paid, in order to
	mitigate the economic effect of insured losses ("loss mitigation securities"). The Company excludes amounts attributable to loss mitigation securities (unless otherwise indicated) from par and Debt Service outstanding, because it manages such securities as investments and not insurance exposure.
	Financial Guaranty
	Debt Service Outstanding
		Gross Debt Service							Net Debt Service
		Outstanding							Outstanding
		March 31,			December 31,				March 31,				December 31,
		2015			2014				2015				2014
		(in millions)
	Public finance	$	565,386		$	587,245			$	533,359			$	553,612
	Structured finance	54,546			59,477				51,300				56,010
	Total financial guaranty	$	619,932		$	646,722			$	584,659			$	609,622
	In addition to the amounts shown in the table above, the Company’s net mortgage guaranty insurance debt service was approximately $113 million as of March 31, 2015 and $127 million as of December 31, 2014, related to loans originated in Ireland.
	Financial Guaranty Portfolio by Internal Rating
	As of March 31, 2015
			Public Finance						Public Finance						Structured Finance						Structured Finance				Total
			U.S.						Non-U.S.						U.S						Non-U.S
	Rating		Net Par			%			Net Par				%		Net Par			%			Net Par		%		Net Par		%
	Category		Outstanding						Outstanding						Outstanding						Outstanding				Outstanding
			(dollars in millions)
	AAA		$	3,563		1.1	%		$	613			2.1	%	$	18,176		47.3	%		$	4,397	57.8	%	$	26,749	6.9	%
	AA		86,521			27.6			2,650				9		8,360			21.7			377		5		97,908		25.2
	A		171,308			54.7			7,091				23.9		2,228			5.8			365		4.7		180,992		46.4
	BBB		44,110			14.1			17,891				60.4		1,843			4.8			1,746		23		65,590		16.9
	BIG		7,942			2.5			1,374				4.6		7,823			20.4			721		9.5		17,860		4.6
	Total net par outstanding (1)		$	313,444		100	%		$	29,619			100	%	$	38,430		100	%		$	7,606	100	%	$	389,099	100	%
	_____________________
	-1	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of March 31, 2015, which are primarily in the BIG category.
	Financial Guaranty Portfolio by Internal Rating
	As of December 31, 2014
			Public Finance						Public Finance						Structured Finance						Structured Finance				Total
			U.S.						Non-U.S.						U.S						Non-U.S
	Rating		Net Par			%			Net Par				%		Net Par			%			Net Par		%		Net Par		%
	Category		Outstanding						Outstanding						Outstanding						Outstanding				Outstanding
			(dollars in millions)
	AAA		$	4,082		1.3	%		$	615			2	%	$	20,037		48.7	%		$	5,409	59.6	%	$	30,143	7.5	%
	AA		90,464			28.1			2,785				8.9		8,213			19.9			503		5.5		101,965		25.3
	A		176,298			54.7			7,192				22.9		2,940			7.1			445		4.9		186,875		46.3
	BBB		43,429			13.5			19,363				61.7		1,795			4.4			1,912		21.1		66,499		16.4
	BIG		7,850			2.4			1,404				4.5		8,186			19.9			807		8.9		18,247		4.5
	Total net par outstanding (1)		$	322,123		100	%		$	31,359			100	%	$	41,171		100	%		$	9,076	100	%	$	403,729	100	%
	_____________________
	-1	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of December 31, 2014, which are primarily in the BIG category.
	In addition to amounts shown in the tables above, the Company had outstanding commitments to provide guaranties of $38 million for structured finance and $410 million for public finance obligations as of March 31, 2015. The structured finance commitments include the unfunded component of pooled corporate and other transactions. The expiration dates for the public finance commitments range between April 9, 2015 and February 25, 2017, with $210 million expiring prior to the date of this filing and an additional $75 million expiring prior to December 31, 2015. The commitments are contingent on the satisfaction of all conditions set forth in them and may expire unused or be canceled at the counterparty’s request. Therefore, the total commitment amount does not necessarily reflect actual future guaranteed amounts.
	Components of BIG Portfolio
	Components of BIG Net Par Outstanding
	(Insurance and Credit Derivative Form)
	As of March 31, 2015
		BIG Net Par Outstanding														Net Par
		BIG 1			BIG 2				BIG 3				Total BIG			Outstanding
								(in millions)
U.S. public finance	$	6,669		$	1,156			$	117			$	7,942		$	313,444
Non-U.S. public finance	863			511				—				1,374			29,619
First lien U.S. residential mortgage-backed securities ("RMBS"):
Prime first lien	49			59				241				349			454
Alt-A first lien	579			436				763				1,778			2,449
Option ARM	9			53				108				170			374
Subprime	179			529				831				1,539			3,935
Second lien U.S. RMBS:
Closed-end second lien	—			19				113				132			212
Home equity lines of credit (“HELOCs”)	1,235			29				240				1,504			1,654
Total U.S. RMBS	2,051			1,125				2,296				5,472			9,078
Triple-X life insurance transactions	—			—				598				598			3,133
Trust preferred securities (“TruPS”)	828			—				327				1,155			4,075
Other structured finance	927			237				155				1,319			29,750
Total	$	11,338		$	3,029			$	3,493			$	17,860		$	389,099
Components of BIG Net Par Outstanding
(Insurance and Credit Derivative Form)
As of December 31, 2014
	BIG Net Par Outstanding														Net Par
	BIG 1			BIG 2				BIG 3				Total BIG			Outstanding
								(in millions)
U.S. public finance	$	6,577		$	1,156			$	117			$	7,850		$	322,123
Non-U.S. public finance	1,402			2				—				1,404			31,359
First lien U.S. RMBS:
Prime first lien	68			33				252				353			471
Alt-A first lien	585			531				725				1,841			2,532
Option ARM	47			18				118				183			407
Subprime	156			654				765				1,575			4,051
Second lien U.S. RMBS:
Closed-end second lien	—			19				115				134			218
HELOCs	1,012			36				509				1,557			1,738
Total U.S. RMBS	1,868			1,291				2,484				5,643			9,417
Triple-X life insurance transactions	—			—				598				598			3,133
TruPS	997			—				336				1,333			4,326
Other structured finance	1,021			240				158				1,419			33,371
Total	$	11,865		$	2,689			$	3,693			$	18,247		$	403,729
BIG Net Par Outstanding
and Number of Risks
As of March 31, 2015
		Net Par Outstanding											Number of Risks(2)
Description		Financial			Credit				Total				Financial		Credit		Total
		Guaranty			Derivative								Guaranty		Derivative
		Insurance(1)											Insurance(1)
		(dollars in millions)
BIG:
Category 1		$	9,887		$	1,451			$	11,338			164		18		182
Category 2		2,345			684				3,029				73		12		85
Category 3		2,705			788				3,493				119		25		144
Total BIG		$	14,937		$	2,923			$	17,860			356		55		411
BIG Net Par Outstanding
and Number of Risks
As of December 31, 2014
		Net Par Outstanding											Number of Risks(2)
Description		Financial			Credit				Total				Financial		Credit		Total
		Guaranty			Derivative								Guaranty		Derivative
		Insurance(1)											Insurance(1)
		(dollars in millions)
BIG:
Category 1		$	10,195		$	1,670			$	11,865			164		18		182
Category 2		2,135			554				2,689				75		14		89
Category 3		2,892			801				3,693				119		24		143
Total BIG		$	15,222		$	3,025			$	18,247			358		56		414
_____________________
(1)    Includes net par outstanding for FG VIEs.
-2	A risk represents the aggregate of the financial guaranty policies that share the same revenue source for purposes of making Debt Service payments.
Exposure to Puerto Rico
The Company insures general obligation bonds of the Commonwealth of Puerto Rico and various obligations of its related authorities and public corporations aggregating $4.9 billion net par as of March 31, 2015. The Company rates $4.7 billion net par of that amount BIG; included in that amount are the obligations of Puerto Rico Highway and Transportation Authority (“PRHTA”) and PREPA.
Puerto Rico has experienced significant general fund budget deficits in recent years. These deficits have been covered primarily with the net proceeds of bond issuances, interim financings provided by Government Development Bank for Puerto Rico (“GDB”) and, in some cases, one-time revenue measures or expense adjustment measures. In addition to high debt levels, Puerto Rico faces a challenging economic environment.
In June 2014, the Puerto Rico legislature passed the Puerto Rico Public Corporation Debt Enforcement and Recovery Act (the "Recovery Act") in order to provide a legislative framework for certain public corporations experiencing severe financial stress to restructure their debt, including PRHTA and PREPA. Subsequently, the Commonwealth stated PREPA might need to seek relief under the Recovery Act due to liquidity constraints.
In August 2014, PREPA entered into forbearance agreements with the GDB, its bank lenders, and bondholders and financial guaranty insurers (including AGM and AGC) that hold or guarantee more than 60% of PREPA's outstanding bonds, in order to address its near-term liquidity issues. Creditors, including AGM and AGC, agreed not to exercise available rights and remedies until March 31, 2015, and the bank lenders agreed to extend the maturity of two revolving lines of credit to the same date. PREPA agreed it would continue to make principal and interest payments on its outstanding bonds, and interest payments on its lines of credit. It also agreed it would develop a five year business plan and a recovery program in respect of its operations; a preliminary business plan was released in December 2014. Subsequently, the parties have extended these forbearance agreements through June 4, 2015. Creditors, including AGM and AGC, are in discussions among themselves and with PREPA regarding potentially extending the forbearance agreements beyond June 4, 2015, but there can be no assurance that such discussions will result in such an extension. PREPA, during the pendency of the Forbearance Agreement, has suspended deposits into the Debt Service Fund and has utilized amounts on deposit in the Debt Service Reserve Fund to pay debt service due on its bonds and other obligations through May 8, 2015.
Investors in bonds issued by PREPA filed suit in the United States District Court for the District of Puerto Rico asserting the Recovery Act violates the U.S. Constitution. On February 6, 2015, the U.S. District Court for the District of Puerto Rico ruled the Recovery Act is preempted by the U.S. Bankruptcy Code and is therefore void; on February 19, 2015, the Commonwealth appealed the ruling to the U.S. Court of Appeals for the First Circuit. In addition, the Commonwealth's Resident Commissioner has introduced a bill to the U.S. Congress that, if passed, would enable the Commonwealth to authorize one or more of its public corporations to restructure their debts under chapter 9 of the U.S Bankruptcy Code if they were to become insolvent. The passage of the Recovery Act, its subsequent invalidation, and the introduction of legislation that would enable the Commonwealth to authorize chapter 9 protection for its public corporations have resulted in uncertainty among investors about the rights of creditors of the Commonwealth and its related authorities and public corporations.
Following the enactment of the Recovery Act, S&P, Moody’s and Fitch Ratings lowered the credit rating of the Commonwealth’s bonds and the ratings on certain of its public corporations. In February, March and April 2015, Moody's, Fitch Ratings and S&P, respectively, each again lowered the credit rating of the Commonwealth's bonds and the ratings on certain of its public corporations. The Commonwealth has disclosed its liquidity has been adversely affected by rating agency downgrades and by the limited market access for its debt, and also noted it has relied on short-term financings and interim loans from the GDB and other private lenders, which reliance has constrained its liquidity and increased its near-term refinancing risk.
In early 2015, Puerto Rico enacted legislation designed to stabilize PRHTA and improve the liquidity of the GDB. The legislation provides for certain tax revenues that would support PRHTA and require the transfer of certain liabilities and revenues from PHRTA to another authority, as well as allowing the transfer of the operations of poorly performing transit facilities to a new authority.
The following tables show the Company’s exposure to general obligation bonds of Puerto Rico and various obligations of its related authorities and public corporations.
Puerto Rico
Gross Par and Gross Debt Service Outstanding
	Gross Par Outstanding							Gross Debt Service Outstanding
	March 31,			December 31,				March 31,				December 31,
	2015			2014				2015				2014
	(in millions)
Previously Subject to the Voided Recovery Act (1)	$	3,059		$	3,058			$	5,252			$	5,326
Not Previously Subject to the Voided Recovery Act	2,977			2,977				4,675				4,748
Total	$	6,036		$	6,035			$	9,927			$	10,074
____________________
-1	On February 6, 2015, the U.S. District Court for the District of Puerto Rico ruled that the Recovery Act is preempted by the Federal Bankruptcy Code and is therefore void. On February 19, 2015, the Commonwealth appealed the ruling to the U.S. Court of Appeals for the First Circuit.
Puerto Rico
Net Par Outstanding
		As of					As of
		31-Mar-15					31-Dec-14
		Total			Internal Rating		Total				Internal Rating
		(in millions)
Exposures Previously Subject to the Voided Recovery Act:
PRHTA (Transportation revenue)		$	844		BB-		$	844			BB-
PREPA		773			B-		772				B-
Puerto Rico Aqueduct and Sewer Authority		384			BB-		384				BB-
PRHTA (Highway revenue)		273			BB		273				BB
Puerto Rico Convention Center District Authority		174			BB-		174				BB-
Total		2,448					2,447
Exposures Not Previously Subject to the Voided Recovery Act:
Commonwealth of Puerto Rico - General Obligation Bonds		1,672			BB		1,672				BB
Puerto Rico Municipal Finance Agency		399			BB-		399				BB-
Puerto Rico Sales Tax Financing Corporation		269			BBB		269				BBB
Puerto Rico Public Buildings Authority		100			BB		100				BB
GDB		33			BB		33				BB
Puerto Rico Infrastructure Finance Authority		18			BB-		18				BB-
University of Puerto Rico		1			BB-		1				BB-
Total		2,492					2,492
Total net exposure to Puerto Rico		$	4,940				$	4,939
The following table shows the scheduled amortization of the general obligation bonds of Puerto Rico and various obligations of its related authorities and public corporations insured and rated BIG by the Company. The Company guarantees payments of interest and principal when those amounts are scheduled to be paid and cannot be required to pay on an accelerated basis. In the event that obligors default on their obligations, the Company would only be required to pay the shortfall between the principal and interest due in any given period and the amount paid by the obligors.
Amortization Schedule of Puerto Rico BIG Net Par Outstanding
and BIG Net Debt Service Outstanding
As of March 31, 2015
	Scheduled BIG Net Par Amortization											Scheduled BIG Net Debt Service Amortization
	Previously Subject to the Voided Recovery Act			Not Previously Subject to the Voided Recovery Act				Total				Previously Subject to the Voided Recovery Act			Not Previously Subject to the Voided Recovery Act			Total
	(in millions)
2015 (April 1 - June 30)	$	0		$	0			$	0			$	2		$	1		$	3
2015 (July 1 - September 30)	126			171				297				186			227			413
2015 (October 1 - December 31)	0			33				33				2			35			37
2016	84			183				267				200			287			487
2017	41			166				207				153			262			415
2018	48			109				157				158			195			353
2019	61			126				187				168			207			375
2020	73			182				255				176			258			434
2021	51			58				109				151			123			274
2022	43			67				110				140			129			269
2023	102			39				141				198			99			297
2024	82			78				160				173			136			309
2025-2029	576			340				916				951			566			1,517
2030-2034	440			387				827				696			542			1,238
2035 -2039	397			272				669				525			304			829
2040 -2044	78			12				90				146			13			159
2045 -2047	246			—				246				272			—			272
Total	$	2,448		$	2,223			$	4,671			$	4,297		$	3,384		$	7,681
Exposure to the Selected European Countries
Several European countries continue to experience significant economic, fiscal and/or political strains such that the likelihood of default on obligations with a nexus to those countries may be higher than the Company anticipated when such factors did not exist. The European countries where the Company has exposure and believes heightened uncertainties exist are: Hungary, Italy, Portugal and Spain (collectively, the “Selected European Countries”). The Company is closely monitoring its exposures in the Selected European Countries where it believes heightened uncertainties exist. The Company’s direct economic exposure to the Selected European Countries (based on par for financial guaranty contracts and notional amount for financial guaranty contracts accounted for as derivatives) is shown in the following table, net of ceded reinsurance.
Net Direct Economic Exposure to Selected European Countries(1)
As of March 31, 2015
	Hungary			Italy				Portugal				Spain			Total
	(in millions)
Sovereign and sub-sovereign exposure:
Non-infrastructure public finance (2)	$	—		$	779			$	91			$	211		$	1,081
Infrastructure finance	265			11				11				120			407
Total sovereign and sub-sovereign exposure	265			790				102				331			1,488
Non-sovereign exposure:
Regulated utilities	—			210				—				—			210
RMBS	174			234				—				—			408
Total non-sovereign exposure	174			444				—				—			618
Total	$	439		$	1,234			$	102			$	331		$	2,106
Total BIG (See Note 5)	$	370		$	—			$	102			$	331		$	803
____________________
-1	While the Company’s exposures are shown in U.S. dollars, the obligations the Company insures are in various currencies, primarily Euros. One of the residential mortgage-backed securities included in the table above includes residential mortgages in both Italy and Germany, and only the portion of the transaction equal to the portion of the original mortgage pool in Italian mortgages is shown in the table.
-2	The exposure shown in the “Non-infrastructure public finance” category is from transactions backed by receivable payments from sub-sovereigns in Italy, Spain and Portugal. Sub-sovereign debt is debt issued by a governmental entity or government backed entity, or supported by such an entity, that is other than direct sovereign debt of the ultimate governing body of the country.
When the Company directly insures an obligation, it assigns the obligation to a geographic location or locations based on its view of the geographic location of the risk. The Company may also have direct exposures to the Selected European Countries in business assumed from unaffiliated monoline insurance companies, in which case the Company depends upon geographic information provided by the primary insurer.
The Company has excluded from the exposure tables above its indirect economic exposure to the Selected European Countries through policies it provides on pooled corporate and commercial receivables transactions. The Company calculates indirect exposure to a country by multiplying the par amount of a transaction insured by the Company times the percent of the relevant collateral pool reported as having a nexus to the country. On that basis, the Company has calculated exposure of $355 million to Selected European Countries (plus Greece) in transactions with $10.0 billion of net par outstanding. The indirect exposure to credits with a nexus to Greece is $11 million across several highly rated pooled corporate obligations with net par outstanding of $483 million.

Financial_Guaranty_Insurance_P

Financial Guaranty Insurance Premiums	3 Months Ended
	Mar. 31, 2015
Insurance [Abstract]
Financial Guaranty Insurance Premiums	Financial Guaranty Insurance Premiums
	The portfolio of outstanding exposures discussed in Note 3, Outstanding Exposure, includes financial guaranty contracts that meet the definition of insurance contracts as well as those that meet the definition of a derivative under GAAP. Amounts presented in this note relate only to financial guaranty insurance contracts, unless otherwise noted. See Note 8, Financial Guaranty Contracts Accounted for as Credit Derivatives for amounts that relate to CDS.
	Net Earned Premiums
		First Quarter
		2015			2014
		(in millions)
	Scheduled net earned premiums	$	96		$	107
	Acceleration of net earned premiums	41			19
	Accretion of discount on net premiums receivable	4			6
	Financial guaranty insurance net earned premiums	141			132
	Other	1			—
	Net earned premiums(1)	$	142		$	132
	___________________
	-1	Excludes $5 million and $17 million for First Quarter 2015 and 2014, respectively, related to consolidated FG VIEs.
	Components of Unearned Premium Reserve
		As of March 31, 2015								As of December 31, 2014
		Gross			Ceded			Net(1)		Gross		Ceded			Net(1)
		(in millions)
	Deferred premium revenue:
	Financial guaranty insurance	$	4,038		$	370		$	3,668	$	4,167	$	387		$	3,780
	Other	1			—			1		0		—			0
	Deferred premium revenue	$	4,039		$	370		$	3,669	$	4,167	$	387		$	3,780
	Contra-paid (2)	88			(5		)	93		94		(6		)	100
	Unearned premium reserve	$	4,127		$	365		$	3,762	$	4,261	$	381		$	3,880
	____________________
	-1	Excludes $125 million and $125 million of deferred premium revenue, and $41 million and $42 million of contra-paid related to FG VIEs as of March 31, 2015 and December 31, 2014, respectively.
	-2	See Note 6, "Financial Guaranty Insurance Losses– Insurance Contracts' Loss Information" for an explanation of "contra-paid".
	Gross Premium Receivable,
	Net of Commissions on Assumed Business
	Roll Forward
		First Quarter
		2015			2014
		(in millions)
	Beginning of period, December 31	$	729		$	876
	Gross premium written, net of commissions on assumed business	36			33
	Gross premiums received, net of commissions on assumed business	(36		)	(53		)
	Adjustments:
	Changes in the expected term	(6		)	(3		)
	Accretion of discount, net of commissions on assumed business	5			7
	Foreign exchange translation	(25		)	2
	Consolidation/deconsolidation of FG VIEs	(4		)	1
	Other adjustments	0			—
	End of period, March 31 (1)	$	699		$	863
	____________________
	-1	Excludes $22 million and $18 million as of March 31, 2015 and March 31, 2014, respectively, related to consolidated FG VIEs. Excludes $1 million related to non-financial guaranty line of business as of March 31, 2015.
	Foreign exchange translation relates to installment premium receivables denominated in currencies other than the U.S. dollar. Approximately 49% and 51% of installment premiums at March 31, 2015 and December 31, 2014 respectively, are denominated in currencies other than the U.S. dollar, primarily the Euro and British Pound Sterling.
	The timing and cumulative amount of actual collections may differ from expected collections in the tables below due to factors such as foreign exchange rate fluctuations, counterparty collectability issues, accelerations, commutations and changes in expected lives.
	Expected Collections of
	Financial Guaranty Gross Premiums Receivable,
	Net of Commissions on Assumed Business
	(Undiscounted)
		As of March 31, 2015
		(in millions)
	2015 (April 1 – June 30)	$	23
	2015 (July 1 – September 30)	24
	2015 (October 1 – December 31)	19
	2016	74
	2017	67
	2018	61
	2019	57
	2020-2024	238
	2025-2029	154
	2030-2034	108
	After 2034	98
Total(1)	$	923
____________________
-1	Excludes expected cash collections on FG VIEs of $28 million.
Scheduled Financial Guaranty Net Earned Premiums
	As of March 31, 2015
	(in millions)
2015 (April 1 – June 30)	$	91
2015 (July 1 – September 30)	89
2015 (October 1 – December 31)	86
2016	334
2017	294
2018	267
2019	244
2020-2024	955
2025-2029	610
2030-2034	373
After 2034	325
Net deferred premium revenue(1)	3,668
Future accretion	198
Total future net earned premiums	$	3,866
____________________
-1	Excludes scheduled net earned premiums on consolidated FG VIEs of $125 million.
Selected Information for Financial Guaranty Policies Paid in Installments
	As of			As of
	31-Mar-15			31-Dec-14
	(dollars in millions)
Premiums receivable, net of commission payable	$	699		$	729
Gross deferred premium revenue	1,334			1,370
Weighted-average risk-free rate used to discount premiums	3.4		%	3.5		%
Weighted-average period of premiums receivable (in years)	9.4			9.4

Expected_Loss_to_be_Paid

Expected Loss to be Paid	3 Months Ended
	Mar. 31, 2015
Expected Losses [Abstract]
Expected Loss to be Paid	Expected Loss to be Paid
	The following tables present a roll forward of the present value of net expected loss to be paid for all contracts, whether accounted for as insurance, credit derivatives or FG VIEs, by sector, after the benefit for net expected recoveries for contractual breaches of representations and warranties ("R&W"). The Company used weighted average risk-free rates for U.S. dollar denominated obligations that ranged from 0.0% to 2.89% as of March 31, 2015 and 0.0% to 2.95% as of December 31, 2014.
	Net Expected Loss to be Paid
	After Net Expected Recoveries for Breaches of R&W
	Roll Forward by Sector
	First Quarter 2015
		Net Expected				Economic Loss				(Paid)			Net Expected
		Loss to be				Development				Recovered			Loss to be
		Paid (Recovered)								Losses (1)			Paid (Recovered)
		as of											as of
		December 31, 2014 (2)											March 31,2015 (2)
		(in millions)
	Public Finance:
	U.S. public finance	$	303			$	9			$	(2	)	$	310
	Non-U.S public finance	45				(3		)		—			42
	Public Finance	348				6				(2		)	352
	Structured Finance:
	U.S. RMBS:
	First lien:
	Prime first lien	4				0				(1		)	3
	Alt-A first lien	304				(5		)		(10		)	289
	Option ARM	(16		)		4				(4		)	(16		)
	Subprime	303				(1		)		(9		)	293
	Total first lien	595				(2		)		(24		)	569
	Second lien:
	Closed-end second lien	8				1				2			11
	HELOCs	(19		)		5				4			(10		)
	Total second lien	(11		)		6				6			1
	Total U.S. RMBS	584				4				(18		)	570
	Triple-X life insurance transactions	161				5				(1		)	165
	TruPS	23				(9		)		—			14
	Other structured finance	57				(8		)		3			52
	Structured Finance	825				(8		)		(16		)	801
	Subtotal	1,173				(2		)		(18		)	1,153
	Other insurance	(4		)		(1		)		6			1
	Total	$	1,169			$	(3	)		$	(12	)	$	1,154
	Net Expected Loss to be Paid
	After Net Expected Recoveries for Breaches of R&W
	Roll Forward by Sector
	First Quarter 2014
		Net Expected				Economic Loss				(Paid)			Net Expected
		Loss to be				Development				Recovered			Loss to be
		Paid (Recovered)								Losses (1)			Paid (Recovered)
		as of											as of
		31-Dec-13											March 31,2014
		(in millions)
	Public Finance:
	U.S. public finance	$	264			$	23			$	(6	)	$	281
	Non-U.S public finance	57				—				—			57
	Public Finance	321				23				(6		)	338
	Structured Finance:
	U.S. RMBS:
	First lien:
	Prime first lien	21				(3		)		—			18
	Alt-A first lien	304				8				(4		)	308
	Option ARM	(9		)		(15		)		(4		)	(28		)
	Subprime	304				(7		)		(2		)	295
	Total first lien	620				(17		)		(10		)	593
	Second lien:
	Closed-end second lien	(11		)		5				2			(4		)
	HELOCs	(116		)		2				5			(109		)
	Total second lien	(127		)		7				7			(113		)
	Total U.S. RMBS	493				(10		)		(3		)	480
	Triple-X life insurance transactions	75				13				(1		)	87
TruPS	51				(19		)		—			32
Other structured finance	45				6				—			51
Structured Finance	664				(10		)		(4		)	650
Subtotal	985				13				(10		)	988
Other insurance	(3		)		(1		)		—			(4		)
Total	$	982			$	12			$	(10	)	$	984
____________________
-1	Net of ceded paid losses, whether or not such amounts have been settled with reinsurers. Ceded paid losses are typically settled 45 days after the end of the reporting period. Such amounts are recorded in reinsurance recoverable on paid losses included in other assets. The Company paid $4 million and $6 million in loss adjustment expenses ("LAE") for First Quarter 2015 and 2014, respectively.
-2	Includes expected LAE to be paid of $13 million as of March 31, 2015 and $16 million as of December 31, 2014.
Net Expected Recoveries from
Breaches of R&W Rollforward
First Quarter 2015
	Future Net				R&W Development				R&W (Recovered)			Future Net
	R&W Benefit as of				and Accretion of				During 2015			R&W Benefit as of
	December 31, 2014				Discount							March 31,2015 (1)
					During 2015
	(in millions)
U.S. RMBS:
First lien:
Prime first lien	$	2			$	(1	)		$	—		$	1
Alt-A first lien	106				(10		)		(2		)	94
Option ARM	15				(20		)		(15		)	(20		)
Subprime	109				(19		)		(3		)	87
Total first lien	232				(50		)		(20		)	162
Second lien:
Closed-end second lien	85				(1		)		(1		)	83
HELOC	—				—				—			—
Total second lien	85				(1		)		(1		)	83
Total	$	317			$	(51	)		$	(21	)	$	245
Net Expected Recoveries from
Breaches of R&W Rollforward
First Quarter 2014
	Future Net				R&W Development				R&W (Recovered)			Future Net
	R&W Benefit as of				and Accretion of				During 2014			R&W Benefit as of
	December 31, 2013				Discount							March 31, 2014
					During 2014
	(in millions)
U.S. RMBS:
First lien:
Prime first lien	$	4			$	(1	)		$	—		$	3
Alt-A first lien	274				3				(8		)	269
Option ARM	173				9				(30		)	152
Subprime	118				28				—			146
Total first lien	569				39				(38		)	570
Second lien:
Closed-end second lien	98				(3		)		—			95
HELOC	45				12				(1		)	56
Total second lien	143				9				(1		)	151
Total	$	712			$	48			$	(39	)	$	721
___________________
(1)    See the section "Breaches of Representations and Warranties" below for eligible assets held in trust.
The following tables present the present value of net expected loss to be paid for all contracts by accounting model, by sector and after the benefit for estimated and contractual recoveries for breaches of R&W.
Net Expected Loss to be Paid (Recovered)
By Accounting Model
As of March 31, 2015
	Financial				FG VIEs(1)				Credit			Total
	Guaranty								Derivatives(2)
	Insurance
	(in millions)
Public Finance:
U.S. public finance	$	310			$	—			$	—		$	310
Non-U.S. public finance	42				—				—			42
Public Finance	352				—				—			352
Structured Finance:
U.S. RMBS:
First lien:
Prime first lien	3				—				—			3
Alt-A first lien	278				17				(6		)	289
Option ARM	(17		)		—				1			(16		)
Subprime	157				69				67			293
Total first lien	421				86				62			569
Second lien:
Closed-end second lien	(24		)		31				4			11
HELOCs	(15		)		5				—			(10		)
Total second lien	(39		)		36				4			1
Total U.S. RMBS	382				122				66			570
Triple-X life insurance transactions	157				—				8			165
TruPS	0				—				14			14
Other structured finance	98				—				(46		)	52
Structured Finance	637				122				42			801
Subtotal	$	989			$	122			$	42		$	1,153
Other												1
Total												$	1,154
Net Expected Loss to be Paid (Recovered)
By Accounting Model
As of December 31, 2014
	Financial				FG VIEs(1)				Credit			Total
	Guaranty								Derivatives(2)
	Insurance
	(in millions)
Public Finance:
U.S. public finance	$	303			$	—			$	—		$	303
Non-U.S. public finance	45				—				—			45
Public Finance	348				—				—			348
Structured Finance:
U.S. RMBS:
First lien:
Prime first lien	2				—				2			4
Alt-A first lien	288				17				(1		)	304
Option ARM	(15		)		—				(1		)	(16		)
Subprime	163				71				69			303
Total first lien	438				88				69			595
Second lien:
Closed-end second lien	(27		)		31				4			8
HELOCs	(26		)		7				—			(19		)
Total second lien	(53		)		38				4			(11		)
Total U.S. RMBS	385				126				73			584
Triple-X life insurance transactions	153				—				8			161
TruPS	1				—				22			23
Other structured finance	102				—				(45		)	57
Structured Finance	641				126				58			825
Subtotal	$	989			$	126			$	58		1,173
Other												(4		)
Total												$	1,169
___________________
(1)    Refer to Note 9, Consolidated Variable Interest Entities.
(2)    Refer to Note 8, Financial Guaranty Contracts Accounted for as Credit Derivatives.
The following tables present the net economic loss development for all contracts by accounting model, by sector and after the benefit for estimated and contractual recoveries for breaches of R&W.
Net Economic Loss Development (Benefit)
By Accounting Model
First Quarter 2015
	Financial				FG VIEs(1)				Credit			Total
	Guaranty								Derivatives(2)
	Insurance
	(in millions)
Public Finance:
U.S. public finance	$	9			$	—			$	—		$	9
Non-U.S. public finance	(3		)		—				—			(3		)
Public Finance	6				—				—			6
Structured Finance:
U.S. RMBS:
First lien:
Prime first lien	1				—				(1		)	0
Alt-A first lien	2				—				(7		)	(5		)
Option ARM	1				—				3			4
Subprime	(4		)		4				(1		)	(1		)
Total first lien	0				4				(6		)	(2		)
Second lien:
Closed-end second lien	1				1				(1		)	1
HELOCs	7				(2		)		—			5
Total second lien	8				(1		)		(1		)	6
Total U.S. RMBS	8				3				(7		)	4
Triple-X life insurance transactions	4				—				1			5
TruPS	(1		)		—				(8		)	(9		)
Other structured finance	(5		)		—				(3		)	(8		)
Structured Finance	6				3				(17		)	(8		)
Subtotal	$	12			$	3			$	(17	)	$	(2	)
Other												(1		)
Total												$	(3	)
Net Economic Loss Development (Benefit)
By Accounting Model
First Quarter 2014
	Financial				FG VIEs(1)				Credit			Total
	Guaranty								Derivatives(2)
	Insurance
	(in millions)
Public Finance:
U.S. public finance	$	23			$	—			$	—		$	23
Non-U.S. public finance	—				—				—			—
Public Finance	23				—				—			23
Structured Finance:
U.S. RMBS:
First lien:
Prime first lien	—				—				(3		)	(3		)
Alt-A first lien	19				(12		)		1			8
Option ARM	(16		)		1				—			(15		)
Subprime	(8		)		(2		)		3			(7		)
Total first lien	(5		)		(13		)		1			(17		)
Second lien:
Closed-end second lien	(1		)		2				4			5
HELOCs	(56		)		58				—			2
Total second lien	(57		)		60				4			7
Total U.S. RMBS	(62		)		47				5			(10		)
Triple-X life insurance transactions	13				—				—			13
TruPS	(1		)		—				(18		)	(19		)
Other structured finance	4				—				2			6
Structured Finance	(46		)		47				(11		)	(10		)
Subtotal	$	(23	)		$	47			$	(11	)	13
Other												(1		)
Total												$	12
_________________
(1)    Refer to Note 9, Consolidated Variable Interest Entities.
(2)    Refer to Note 8, Financial Guaranty Contracts Accounted for as Credit Derivatives.
Selected U.S. Public Finance Transactions
The Company insures general obligation bonds of the Commonwealth of Puerto Rico and various obligations of its related authorities and public corporations aggregating $4.9 billion net par as of March 31, 2015. The Company rates $4.7 billion net par of that amount BIG. For additional information regarding the Company's exposure to general obligations of Commonwealth of Puerto Rico and various obligations of its related authorities and public corporations, please refer to "Exposure to Puerto Rico" in Note 3, Outstanding Exposure.
On February 25, 2015, a plan of adjustment resolving the bankruptcy filing of the City of Stockton, California under chapter 9 of the U.S. Bankruptcy Code became effective. As of March 31, 2015, the Company’s net exposure subject to the plan consists of $117 million of pension obligation bonds. As part of the plan settlement, the City will repay the pension obligation bonds from certain fixed payments and certain variable payments contingent on the City's revenue growth. The Company agreed as part of the plan to cancel its $40 million of the City’s lease revenue bonds in exchange for the irrevocable option to take title to the office building that served as collateral for the lease revenue bonds. The Company also receives net rental payments from the office building. The Company no longer reflects the canceled lease revenue bonds as outstanding insured net par, but instead the financial statements reflect an investment in the office building and related lease revenue and expenses. As of March 31, 2015, the office building is carried at approximately $30 million and is reported as part of Other Assets.
The Company has $336 million of net par exposure to the Louisville Arena Authority. The bond proceeds were used to construct the KFC Yum Center, home to the University of Louisville men's and women's basketball teams. Actual revenues available for Debt Service are well below original projections, and under the Company's internal rating scale, the transaction is BIG.
In December 2014, the City of Detroit emerged from bankruptcy under chapter 9 of the U.S. Bankruptcy Code. The Company still expects to make debt service payments on the 15.5% of the City’s unlimited tax general obligation (“UTGO”) that were not exchanged as part of the related settlement. As of March 31, 2015, these bonds had a net par outstanding of $20 million.
The Company projects that its total net expected loss across its troubled U.S. public finance credits as of March 31, 2015, which incorporated the likelihood of the outcomes mentioned above, will be $310 million, compared with a net expected loss of $303 million as of December 31, 2014. Economic loss development in First Quarter 2015 was $9 million which was primarily attributable to certain Puerto Rico exposures.
Certain Selected European Country Transactions
The Company insures and reinsures credits with sub-sovereign exposure to various Spanish and Portuguese issuers where a Spanish and Portuguese sovereign default may cause the regions also to default. The Company's gross exposure to these Spanish and Portuguese credits is $461 million and $114 million, respectively and exposure net of reinsurance for Spanish and Portuguese credits is $331 million and $102 million, respectively. The Company rates most of these issuers in the BB category due to the financial condition of Spain and Portugal and their dependence on the sovereign. The Company's Hungary exposure is to infrastructure bonds dependent on payments from Hungarian governmental entities and covered mortgage bonds issued by Hungarian banks. The Company's gross exposure to these Hungarian credits is $465 million and its exposure net of reinsurance is $439 million, most of which is rated BIG. The Company estimated net expected losses of $42 million related to these Spanish, Portuguese and Hungarian credits. The positive economic loss development of approximately $3 million during First Quarter 2015 was primarily related to changes in the exchange rate between the Euro and US Dollar.
Infrastructure Finance
The Company has insured exposure of approximately $3.0 billion to infrastructure transactions with refinancing risk as to which the Company may need to make claim payments that it did not anticipate paying when the policies were issued. Although the Company may not experience ultimate loss on a particular transaction, the aggregate amount of the claim payments may be substantial and reimbursement may not occur for an extended time. These transactions generally involve long-term infrastructure projects that were financed by bonds that mature prior to the expiration of the project concession. The Company expects the cash flows from these projects to be sufficient to repay all of the debt over the life of the project concession, but also expects the debt to be refinanced in the market at or prior to its maturity. If the issuer is unable to refinance the debt due to market conditions, the Company may have to pay a claim when the debt matures, and then recover its payment from cash flows produced by the project in the future. The Company generally projects that in most scenarios it will be fully reimbursed for such payments. However, the recovery of the payments is uncertain and may take from 10 to 35 years, depending on the transaction and the performance of the underlying collateral. The Company estimates total claims for the two largest transactions with significant refinancing risk, assuming no refinancing, and based on certain performance assumptions could be $1.7 billion on a gross basis; such claims would be payable from 2017 through 2022.
Approach to Projecting Losses in U.S. RMBS
The Company projects losses on its insured U.S. RMBS on a transaction-by-transaction basis by projecting the performance of the underlying pool of mortgages over time and then applying the structural features (i.e., payment priorities and tranching) of the RMBS to the projected performance of the collateral over time. The resulting projected claim payments or reimbursements are then discounted using risk-free rates. For transactions where the Company projects it will receive recoveries from providers of R&W, it projects the amount of recoveries and either establishes a recovery for claims already paid or reduces its projected claim payments accordingly.
The further behind a mortgage borrower falls in making payments, the more likely it is that he or she will default. The rate at which borrowers from a particular delinquency category (number of monthly payments behind) eventually default is referred to as the “liquidation rate.” The Company derives its liquidation rate assumptions from observed roll rates, which are the rates at which loans progress from one delinquency category to the next and eventually to default and liquidation. The Company applies liquidation rates to the mortgage loan collateral in each delinquency category and makes certain timing assumptions to project near-term mortgage collateral defaults from loans that are currently delinquent.
Mortgage borrowers that are not more than one payment behind (generally considered performing borrowers) have demonstrated an ability and willingness to pay throughout the recession and mortgage crisis, and as a result are viewed as less likely to default than delinquent borrowers. Performing borrowers that eventually default will also need to progress through delinquency categories before any defaults occur. The Company projects how many of the currently performing loans will default and when they will default, by first converting the projected near term defaults of delinquent borrowers derived from liquidation rates into a vector of conditional default rates ("CDR"), then projecting how the conditional default rates will develop over time. Loans that are defaulted pursuant to the conditional default rate after the near-term liquidation of currently delinquent loans represent defaults of currently performing loans and projected re-performing loans. A conditional default rate is the outstanding principal amount of defaulted loans liquidated in the current month divided by the remaining outstanding amount of the whole pool of loans (or “collateral pool balance”). The collateral pool balance decreases over time as a result of scheduled principal payments, partial and whole principal prepayments, and defaults.
In order to derive collateral pool losses from the collateral pool defaults it has projected, the Company applies a loss severity. The loss severity is the amount of loss the transaction experiences on a defaulted loan after the application of net proceeds from the disposal of the underlying property. The Company projects loss severities by sector based on its experience to date. The Company continues to update its evaluation of these exposures as new information becomes available.
The Company has been enforcing claims for breaches of R&W regarding the characteristics of the loans included in the collateral pools. The Company calculates a credit for R&W recoveries to include in its cash flow projections. Where the Company has an agreement with an R&W provider (such as its agreements with Bank of America, Deutsche Bank and UBS, which are described in more detail under "Breaches of Representations and Warranties" below), that credit is based on the agreement or potential agreement. Where the Company does not have an agreement with the R&W provider but the Company believes the R&W provider to be economically viable, the Company estimates what portion of its past and projected future claims it believes will be reimbursed by that provider.
The Company projects the overall future cash flow from a collateral pool by adjusting the payment stream from the principal and interest contractually due on the underlying mortgages for the collateral losses it projects as described above; assumed voluntary prepayments; and servicer advances. The Company then applies an individual model of the structure of the transaction to the projected future cash flow from that transaction’s collateral pool to project the Company’s future claims and claim reimbursements for that individual transaction. Finally, the projected claims and reimbursements are discounted using risk-free rates. The Company runs several sets of assumptions regarding mortgage collateral performance, or scenarios, and probability weights them.
The ultimate performance of the Company’s RMBS transactions remains highly uncertain, may differ from the Company's projections and may be subject to considerable volatility due to the influence of many interrelated factors that are difficult to predict, including the level and timing of loan defaults, changes in housing prices, results from the Company’s loss mitigation activities and other variables. The Company will continue to monitor the performance of its RMBS exposures and will adjust its RMBS loss projection assumptions and scenarios based on actual performance and management’s view of future performance. If actual experience differs from the Company’s assumptions, the losses incurred could be materially different from the estimate.
The Company's RMBS loss projection methodology assumes that the housing and mortgage markets will continue improving. Each period the Company makes a judgment as to whether to change the assumptions it uses to make RMBS loss projections based on its observation during the period of the performance of its insured transactions (including early stage delinquencies, late stage delinquencies and loss severity) as well as the residential property market and economy in general, and, to the extent it observes changes, it makes a judgment as whether those changes are normal fluctuations or part of a trend.
First Quarter 2015 U.S. RMBS Loss Projections
Based on its observation during the period of the performance of its insured transactions (including early stage delinquencies, late stage delinquencies and loss severity) as well as the residential property market and economy in general, the Company chose to use the same general assumptions to project RMBS losses as of March 31, 2015 as it used as of December 31, 2014, except that, for its first lien RMBS loss projections it again this quarter shortened by three months the period it is projecting it will take in the base case to reach the final CDR.
U.S. First Lien RMBS Loss Projections: Alt-A First Lien, Option ARM, Subprime and Prime
The majority of projected losses in first lien RMBS transactions are expected to come from non-performing mortgage loans (those that have been modified or have been delinquent in the previous 12 months, are two or more payments behind, are in foreclosure or that have been foreclosed and so the RMBS issuer owns the underlying real estate). Changes in the amount of non-performing loans from the amount projected in the previous period are one of the primary drivers of loss development in this portfolio. In order to determine the number of defaults resulting from these delinquent and foreclosed loans, the Company applies a liquidation rate assumption to loans in each of various non-performing categories. The Company arrived at its liquidation rates based on data purchased from a third party provider and assumptions about how delays in the foreclosure process and loan modifications may ultimately affect the rate at which loans are liquidated. Each year the Company reviews the most recent twenty-four months of this data and adjusts its liquidation rates based on its observations. The following table shows liquidation assumptions for various non-performing categories.
First Lien Liquidation Rates
	March 31, 2015		December 31, 2014
Current Loans Modified in the Previous 12 Months
Alt A and Prime	25%		25%
Option ARM	25		25
Subprime	25		25
Current Loans Delinquent in the Previous 12 Months
Alt A and Prime	25		25
Option ARM	25		25
Subprime	25		25
30 – 59 Days Delinquent
Alt A and Prime	35		35
Option ARM	40		40
Subprime	35		35
60 – 89 Days Delinquent
Alt A and Prime	50		50
Option ARM	55		55
Subprime	40		40
90+ Days Delinquent
Alt A and Prime	60		60
Option ARM	65		65
Subprime	55		55
Bankruptcy
Alt A and Prime	45		45
Option ARM	50		50
Subprime	40		40
Foreclosure
Alt A and Prime	75		75
Option ARM	80		80
Subprime	70		70
Real Estate Owned
All	100		100
While the Company uses liquidation rates as described above to project defaults of non-performing loans (including current loans modified or delinquent within the last 12 months), it projects defaults on presently current loans by applying a CDR trend. The start of that CDR trend is based on the defaults the Company projects will emerge from currently nonperforming, recently nonperforming and modified loans. The total amount of expected defaults from the non-performing loans is translated into a constant CDR (i.e., the CDR plateau), which, if applied for each of the next 36 months, would be sufficient to produce approximately the amount of defaults that were calculated to emerge from the various delinquency categories. The CDR thus calculated individually on the delinquent collateral pool for each RMBS is then used as the starting point for the CDR curve used to project defaults of the presently performing loans.
In the base case, after the initial 36-month CDR plateau period, each transaction’s CDR is projected to improve over 12 months to an intermediate CDR (calculated as 20% of its CDR plateau); that intermediate CDR is held constant for 36 months and then trails off in steps to a final CDR of 5% of the CDR plateau. In the base case, the Company assumes the final CDR will be reached eight years and three months after the initial 36-month CDR plateau period, which is three months shorter than assumed as of December 31, 2014 but the same calendar date as it assumed as of June 30, 2014. Under the Company’s methodology, defaults projected to occur in the first 36 months represent defaults that can be attributed to loans that were modified or delinquent in the last 12 months or that are currently delinquent or in foreclosure, while the defaults projected to occur using the projected CDR trend after the first 36 month period represent defaults attributable to borrowers that are currently performing or are projected to reperform.
Another important driver of loss projections is loss severity, which is the amount of loss the transaction incurs on a loan after the application of net proceeds from the disposal of the underlying property. Loss severities experienced in first lien transactions have reached historic high levels, and the Company is assuming in the base case that these high levels generally will continue for another 18 months. The Company determines its initial loss severity based on actual recent experience. The Company then assumes that loss severities begin returning to levels consistent with underwriting assumptions beginning after the initial 18 month period, declining to 40% in the base case over 2.5 years. Beginning for December 31, 2014, the Company differentiated the loss severity assumptions depending on the vintage of the transaction, as shown in the table below.
The following table shows the range as well as the average, weighted by outstanding net insured par, for key assumptions used in the calculation of expected loss to be paid for individual transactions for direct vintage 2004 - 2008 first lien U.S. RMBS.
Key Assumptions in Base Case Expected Loss Estimates
First Lien RMBS(1)
	As of							As of
	31-Mar-15							31-Dec-14
	Range					Weighted Average		Range				Weighted Average
Alt-A First Lien
Plateau CDR	2.6	%	–	13.10%		7.40%		2	%	–	13.40%	7.30%
Intermediate CDR	0.5	%	–	2.60%		1.50%		0.4	%	–	2.70%	1.50%
Period until intermediate CDR	48 months							48 months
Final CDR	0.1	%	–	0.70%		0.30%		0.1	%	–	0.70%	0.30%
Initial loss severity:
2005 and prior	60.00%							60.00%
2006	70.00%							70.00%
2007	65.00%							65.00%
Initial conditional prepayment rate ("CPR")	2.7	%	–	22.40%		8.10%		1.7	%	–	21.00%	7.70%
Final CPR(2)	15	%	–	22.40%		15.20%		15%
Option ARM
Plateau CDR	4.5	%	–	12.90%		9.90%		4.3	%	–	14.20%	10.60%
Intermediate CDR	0.9	%	–	2.60%		2.00%		0.9	%	–	2.80%	2.10%
Period until intermediate CDR	48 months							48 months
Final CDR	0.2	%	–	0.60%		0.50%		0.2	%	–	0.70%	0.50%
Initial loss severity:
2005 and prior	60.00%							60.00%
2006	70.00%							70.00%
2007	65.00%							65.00%
Initial CPR	1.8	%	–	12.70%		4.90%		1.1	%	–	11.80%	4.90%
Final CPR(2)	15%							15%
Subprime
Plateau CDR	4.8	%	–	14.40%		10.20%		4.9	%	–	15.00%	10.60%
Intermediate CDR	1	%	–	2.90%		2.00%		1	%	–	3.00%	2.10%
Period until intermediate CDR	48 months							48 months
Final CDR	0.2	%	–	0.70%		0.40%		0.2	%	–	0.70%	0.40%
Initial loss severity:
2005 and prior	75.00%							75.00%
2006	90.00%							90.00%
2007	90.00%							90.00%
Initial CPR	0	%	–	9.70%		4.70%		0	%	–	10.50%	6.10%
Final CPR(2)	15%							15%
____________________
(1)                                Represents variables for most heavily weighted scenario (the “base case”).
(2)	For transactions where the initial CPR is higher than the final CPR, the initial CPR is held constant and the final CPR is not used.
The rate at which the principal amount of loans is voluntarily prepaid may impact both the amount of losses projected (since that amount is a function of the conditional default rate, the loss severity and the loan balance over time) as well as the amount of excess spread (the amount by which the interest paid by the borrowers on the underlying loan exceeds the amount of interest owed on the insured obligations). The assumption for the voluntary CPR follows a similar pattern to that of the conditional default rate. The current level of voluntary prepayments is assumed to continue for the plateau period before gradually increasing over 12 months to the final CPR, which is assumed to be 15% in the base case. For transactions where the initial CPR is higher than the final CPR, the initial CPR is held constant and the final CPR is not used. These assumptions are the same as those the Company used for December 31, 2014.
In estimating expected losses, the Company modeled and probability weighted sensitivities for first lien transactions by varying its assumptions of how fast a recovery is expected to occur. One of the variables used to model sensitivities was how quickly the conditional default rate returned to its modeled equilibrium, which was defined as 5% of the initial conditional default rate. The Company also stressed CPR and the speed of recovery of loss severity rates. The Company probability weighted a total of five scenarios (including its base case) as of March 31, 2015. The Company used a similar approach to establish its pessimistic and optimistic scenarios as of March 31, 2015 as it used as of December 31, 2014, increasing and decreasing the periods of stress from those used in the base case.
In a somewhat more stressful environment than that of the base case, where the conditional default rate plateau was extended six months (to be 42 months long) before the same more gradual conditional default rate recovery and loss severities were assumed to recover over 4.5 rather than 2.5 years (and subprime loss severities were assumed to recover only to 60% and Option ARM and Alt A loss severities to only 45%), expected loss to be paid would increase from current projections by approximately $38 million for Alt-A first liens, $2 million for Option ARM, $72 million for subprime and $1 million for prime transactions.
In an even more stressful scenario where loss severities were assumed to rise and then recover over nine years and the initial ramp-down of the conditional default rate was assumed to occur over 15 months and other assumptions were the same as the other stress scenario, expected loss to be paid would increase from current projections by approximately $84 million for Alt-A first liens, $12 million for Option ARM, $99 million for subprime and $4 million for prime transactions.
In a scenario with a somewhat less stressful environment than the base case, where conditional default rate recovery was somewhat less gradual, expected loss to be paid would decrease from current projections by approximately $0.4 million for Alt-A first lien, $14 million for Option ARM, $11 million for subprime and $0.1 million for prime transactions.
In an even less stressful scenario where the conditional default rate plateau was six months shorter (30 months, effectively assuming that liquidation rates would improve) and the conditional default rate recovery was more pronounced, (including an initial ramp-down of the conditional default rate over nine months), expected loss to be paid would decrease from current projections by approximately $26 million for Alt-A first lien, $26 million for Option ARM, $47 million for subprime and $0.5 million for prime transactions.
U.S. Second Lien RMBS Loss Projections: HELOCs and Closed-End Second Lien
The Company believes the primary variable affecting its expected losses in second lien RMBS transactions is the amount and timing of future losses in the collateral pool supporting the transactions. Expected losses are also a function of the structure of the transaction; the voluntary prepayment rate (typically also referred to as CPR of the collateral); the interest rate environment; and assumptions about the draw rate and loss severity.
The following table shows the range as well as the average, weighted by outstanding net insured par, for key assumptions for the calculation of expected loss to be paid for individual transactions for direct vintage 2004 - 2008 second lien U.S. RMBS.
Key Assumptions in Base Case Expected Loss Estimates
Second Lien RMBS(1)
HELOC key assumptions	As of							As of
	31-Mar-15							31-Dec-14
	Range					Weighted Average		Range				Weighted Average
Plateau CDR	2.3	%	–	7.50%		4.40%		2.8	%	–	6.80%	4.10%
Final CDR trended down to	0.5	%	–	3.20%		1.20%		0.5	%	–	3.20%	1.20%
Period until final CDR	34 months							34 months
Initial CPR	6.9	%	–	23.20%		10.20%		6.9	%	–	21.80%	11.00%
Final CPR(2)	10	%	–	23.20%		15.20%		15	%	–	21.80%	15.50%
Loss severity	90	%	–	98.00%		90.40%		90	%	–	98.00%	90.40%
Closed-end second lien key assumptions	As of							As of
	31-Mar-15							31-Dec-14
	Range					Weighted Average		Range				Weighted Average
Plateau CDR	4.7	%	–	12.40%		6.90%		5.5	%	–	12.50%	7.20%
Final CDR trended down to	3.5	%	–	9.10%		4.90%		3.5	%	–	9.10%	4.90%
Period until final CDR	34 months							34 months
Initial CPR	3.4	%	–	11.80%		7.60%		2.8	%	–	13.90%	9.90%
Final CPR(2)	15%							15%
Loss severity	98%							98%
____________________
-1	Represents variables for most heavily weighted scenario (the “base case”).
(2)	For transactions where the initial CPR is higher than the final CPR, the initial CPR is held constant and the final CPR is not used.
In second lien transactions the projection of near-term defaults from currently delinquent loans is relatively straightforward because loans in second lien transactions are generally “charged off” (treated as defaulted) by the securitization’s servicer once the loan is 180 days past due. Most second lien transactions report the amount of loans in five monthly delinquency categories (i.e., 30-59 days past due, 60-89 days past due, 90-119 days past due, 120-149 days past due and 150-179 days past due). The Company estimates the amount of loans that will default over the next five months by calculating current representative liquidation rates (the percent of loans in a given delinquency status that are assumed to ultimately default) from selected representative transactions and then applying an average of the preceding twelve months’ liquidation rates to the amount of loans in the delinquency categories. The amount of loans projected to default in the first through fifth months is expressed as a CDR. The first four months’ CDR is calculated by applying the liquidation rates to the current period past due balances (i.e., the 150-179 day balance is liquidated in the first projected month, the 120-149 day balance is liquidated in the second projected month, the 90-119 day balance is liquidated in the third projected month and the 60-89 day balance is liquidated in the fourth projected month). For the fifth month the CDR is calculated using the average 30-59 day past due balances for the prior three months, adjusted as necessary to reflect one-time service events. The fifth month CDR is then used as the basis for the plateau period that follows the embedded five months of losses.
For the base case scenario, the CDR (the “plateau CDR”) was held constant for one month. Once the plateau period has ended, the CDR is assumed to gradually trend down in uniform increments to its final long-term steady state CDR. (The long-term steady state CDR is calculated as the constant CDR that would have yielded the amount of losses originally expected at underwriting.) In the base case scenario, the time over which the CDR trends down to its final CDR is 28 months. Therefore, the total stress period for second lien transactions is 34 months, comprising five months of delinquent data, a one month plateau period and 28 months of decrease to the steady state CDR, the same as of December 31, 2014.
HELOC loans generally permit the borrower to pay only interest for an initial period (often ten years) and, after that period, require the borrower to make both the monthly interest payment and a monthly principal payment, and so increase the borrower's aggregate monthly payment. Some of the HELOC loans underlying the Company's insured HELOC transactions have reached their principal amortization period. The Company has observed that for loans reaching their principal amortization period planned servicer intervention is not completely effective. Thus, most of the HELOC projections incorporate an assumption that 7.5% of loans reaching their amortization periods will default around the time of the payment increase. These projected defaults are in addition to those generated using the CDR curve as described above. This assumption is the same as December 31, 2014.
When a second lien loan defaults, there is generally a very low recovery. The Company had assumed as of December 31, 2014 that it will recover only 10% of the collateral defaulting in the future and declining additional amounts on post-default receipts on previously defaulted collateral. This is the same as at December 31, 2014.
The rate at which the principal amount of loans is prepaid may impact both the amount of losses projected as well as the amount of excess spread. In the base case, the current CPR (based on experience of the most recent three quarters) is assumed to continue until the end of the plateau before gradually increasing to the final CPR over the same period the CDR decreases. For transactions where the initial CPR is higher than the final CPR, the initial CPR is held constant and the final CPR is not used. The final CPR is assumed to be 15% for both HELOC and closed-end second lien transactions, which is lower than the historical average but reflects the Company’s continued uncertainty about the projected performance of the borrowers in these transactions. This pattern is consistent with how the Company modeled the CPR at December 31, 2014. To the extent that prepayments differ from projected levels it could materially change the Company’s projected excess spread and losses.
The Company uses a number of other variables in its second lien loss projections, including the spread between relevant interest rate indices and HELOC draw rates (the amount of new advances provided on existing HELOCs expressed as a percentage of the current pool balance). These variables have been relatively stable and in the relevant ranges have less impact on the projection results than the variables discussed above. However, in a number of HELOC transactions the servicers have been modifying poorly performing loans from floating to fixed rates, and, as a result, rising interest rates would negatively impact the excess spread available from these modified loans to support the transactions.  The Company incorporated these modifications in its assumptions.
In estimating expected losses, the Company modeled and probability weighted three possible CDR curves applicable to the period preceding the return to the long-term steady state CDR using the same approaches and weightings as it did as of December 31, 2014. The Company believes that the level of the elevated CDR and the length of time it will persist is the primary driver behind the likely amount of losses the collateral will suffer. The Company continues to evaluate the assumptions affecting its modeling results.
The Company’s base case assumed a one month CDR plateau and a 28 month ramp-down (for a total stress period of 34 months). The Company also modeled a scenario with a longer period of elevated defaults and another with a shorter period of elevated defaults. Increasing the CDR plateau to four months and increasing the ramp-down by five months to 33 months (for a total stress period of 42 months) would increase the expected loss by approximately $14 million for HELOC transactions and $1 million for closed-end second lien transactions. On the other hand, keeping the CDR plateau at one month but decreasing the length of the CDR ramp-down to 18 months (for a total stress period of 24 months) would decrease the expected loss by approximately $14 million for HELOC transactions and $1 million for closed-end second lien transactions.
Breaches of Representations and Warranties
Generally, when mortgage loans are transferred into a securitization, the loan originator(s) and/or sponsor(s) provide R&W that the loans meet certain characteristics, and a breach of such R&W often requires that the loan be repurchased from the securitization. In many of the transactions the Company insures, it is in a position to enforce these R&W provisions. The Company has pursued breaches of R&W on a loan-by-loan basis or in cases where a provider of R&W refused to honor its repurchase obligations, the Company sometimes chose to initiate litigation. The Company's success in pursuing these strategies permitted the Company to enter into agreements with R&W providers under which those providers made payments to the Company, agreed to make payments to the Company in the future, and / or repurchased loans from the transactions, all in return for releases of related liability by the Company. In some instances, the entity providing the R&W (or an affiliate of that entity) also benefited from credit protection sold by the Company through a CDS, and the Company entered into an agreement terminating the CDS protection it provided (and so avoiding future losses on that transaction), again in return for releases of related liability by the Company and in certain instances other consideration. Such agreements with R&W providers provide the Company with many of the benefits of pursuing the R&W claims on a loan by loan basis or through litigation, but without the related expense and uncertainty. The Company continues to pursue these strategies against R&W providers with which it does not yet have agreements.
Through March 31, 2015, the Company has caused entities providing R&Ws to pay, or agree to pay, or to terminate insurance protection on future projected losses of, approximately $4.2 billion (gross of reinsurance) in respect of their R&W liabilities for transactions in which the Company has provided insurance and included in its net expected loss estimates as of March 31, 2015 an estimated net benefit of $245 million, (net of reinsurance). Most of this net benefit is projected to be received pursuant to existing agreements with R&W providers, although some is projected to be received in connection with transactions where the company does not yet have such an agreement. Most of the amount projected to be received pursuant to existing agreements with R&W providers benefits from eligible assets placed in trusts to collateralize the R&W provider’s future reimbursement obligation, with the amount of such collateral subject to increase or decrease from time to time as determined by rating agency requirements. Currently the Company has agreements with three counterparties where a future reimbursement obligation is collateralized by eligible assets held in trust:
•	Bank of America. Under the Company's agreement with Bank of America Corporation and certain of its subsidiaries (“Bank of America”), Bank of America agreed to reimburse the Company for 80% of claims on the first lien transactions covered by the agreement that the Company pays in the future, until the aggregate lifetime collateral losses (not insurance losses or claims) on those transactions reach $6.6 billion. As of March 31, 2015 aggregate lifetime collateral losses on those transactions was $4.2 billion, and the Company was projecting in its base case that such collateral losses would eventually reach $5.2 billion. Bank of America's reimbursement obligation is secured by $569 million of collateral held in trust for the Company's benefit.
•	Deutsche Bank. Under the Company's May 2012 agreement with Deutsche Bank AG and certain of its affiliates (collectively, “Deutsche Bank”), Deutsche Bank agreed to reimburse the Company for certain claims it pays in the future on eight first and second lien transactions, including 80% of claims it pays on those transactions until the aggregate lifetime claims (before reimbursement) reach $319 million. As of March 31, 2015, the Company was projecting in its base case that such aggregate lifetime claims would remain below $319 million. In the event aggregate lifetime claims paid exceed $389 million, Deutsche Bank must reimburse the Company for 85% of such claims paid (in excess of $389 million) until such claims paid reach $600 million.
When the agreement was first signed, Deutsche Bank was also required to reimburse AGC for future claims it pays on certain RMBS resecuritizations. AGC and Deutsche Bank terminated one of the resecuritization transactions on October 10, 2013, another on September 12, 2014 and two more in the fourth quarter of 2014. In the fourth quarter of 2014, AGC and Deutsche Bank also terminated one other BIG transaction under which AGC had provided credit protection to Deutsche Bank through a CDS. In connection with the 2014 terminations, AGC and Deutsche Bank agreed to terminate Deutsche Bank’s reimbursement obligation on all of the RMBS resecuritizations, and AGC made a termination payment to Deutsche Bank and released some of the collateral that had been held in trust. Deutsche Bank remains liable to reimburse the Company for certain claims it pays on eight first and second lien transactions, as described above, and such reimbursement obligation remains secured by $78 million of collateral held in trust for the Company’s benefit.
•	UBS. On May 6, 2013, the Company entered into an agreement with UBS Real Estate Securities Inc. and affiliates ("UBS") and a third party resolving the Company’s claims and liabilities related to specified RMBS transactions that were issued, underwritten or sponsored by UBS and insured by AGM or AGC under financial guaranty insurance policies. Under the agreement, UBS agreed to reimburse the Company for 85% of future losses on three first lien RMBS transactions, and such reimbursement obligation is secured by $95 million of collateral held in trust for the Company's benefit.
For the expected recovery from breaches of R&W in transactions not covered by agreements as of March 31, 2015, the Company did not incorporate any gain contingencies from potential litigation in its estimated repurchases. The amount the Company will ultimately recover related to such contractual R&W is uncertain and subject to a number of factors including the counterparty's ability to pay, the number and loss amount of loans determined to have breached R&W and, potentially, negotiated settlements or litigation recoveries. As such, the Company's estimate of recoveries is uncertain and actual amounts realized may differ significantly from these estimates. In arriving at the expected recovery from breaches of R&W not already covered by agreements, the Company considered the creditworthiness of the provider of the R&W, the number of breaches found on defaulted loans, the success rate in resolving these breaches across those transactions where material repurchases have been made and the potential amount of time until the recovery is realized. The calculation of expected recovery from breaches of such contractual R&W involved a variety of scenarios which ranged from the Company recovering substantially all of the losses it incurred due to violations of R&W to the Company realizing limited recoveries. These scenarios were probability weighted in order to determine the recovery incorporated into the Company's estimate of expected losses. This approach was used for both loans that had already defaulted and those assumed to default in the future. The Company adjusts the calculation of its expected recovery from breaches of R&W based on changing facts and circumstances with respect to each counterparty and transaction.
The Company uses the same RMBS projection scenarios and weightings to project its future R&W benefit as it uses to project RMBS losses on its portfolio. To the extent the Company increases its loss projections, the R&W benefit (whether pursuant to an R&W agreement or not) generally will also increase, subject to the agreement limits and thresholds described above. Similarly, to the extent the Company decreases its loss projections, the R&W benefit (whether pursuant to an R&W agreement or not) generally will also decrease, subject to the agreement limits and thresholds described above.
The number of risks subject to R&W recovery is 30, with related net debt service of 2.1 billion as of March 31, 2015 compared to 29 with related net debt service of $2.1 billion as of December 31, 2014. Included in these amounts is net debt service related to transactions not yet subject to an agreement. A risk represents the aggregate of the financial guaranty policies that share the same revenue source for purposes of making Debt Service payments.
The following table provides a breakdown of the development and accretion amount in the roll forward of estimated recoveries associated with claims for breaches of R&W.
Components of R&W Development
	First Quarter
	2015				2014
	(in millions)
Estimated increase (decrease) in defaults that will result in additional (lower) breaches(1)	$	(52	)		$	0
Inclusion or removal of deals with breaches of R&W during period	0				—
Change in recovery assumptions	—				10
Settlements and anticipated settlements	—				35
Accretion of discount on balance	1				3
Total	$	(51	)		$	48
____________________
-1	The negative R&W development is offset by higher anticipated cash flows in the covered transactions that were related to a third party settlement.
Triple-X Life Insurance Transactions
The Company’s $3.1 billion net par of Triple-X life insurance transactions as of March 31, 2015 include $598 million rated BIG in two transactions. The Triple-X life insurance transactions are based on discrete blocks of individual life insurance business.
In older vintage Triple-X transactions, which include the Company's two BIG Triple-X transactions, the monies raised by the sale of the notes insured by the Company were used to capitalize a special purpose vehicle that provides reinsurance to a life insurer or reinsurer. The monies are invested at inception in accounts managed by third-party investment managers. In the case of the two BIG Triple-X life insurance transactions, material amounts of their assets were invested in U.S. RMBS. Based on its analysis of the information currently available, including estimates of future investment performance, and projected credit impairments on the invested assets and performance of the blocks of life insurance business at March 31, 2015, the Company’s projected net expected loss to be paid is $165 million. The economic loss development during First Quarter 2015 was approximately $5 million, which was due primarily to changes in the risk free rates used to discount the losses and life insurance projections.
Trust Preferred Securities Collateralized Debt Obligations
The Company has insured or reinsured $4.1 billion of net par (72% of which is in CDS form) of collateralized debt obligations (“CDOs”) backed by TruPS and similar debt instruments, or “TruPS CDOs.” Of the $4.1 billion, $1.2 billion is rated BIG. The underlying collateral in the TruPS CDOs consists of subordinated debt instruments such as TruPS issued by bank holding companies and similar instruments issued by insurance companies, real estate investment trusts (“REITs”) and other real estate related issuers.
The Company projects losses for TruPS CDOs by projecting the performance of the asset pools across several scenarios (which it weights) and applying the CDO structures to the resulting cash flows. At March 31, 2015, the Company has projected expected losses to be paid for TruPS CDOs of $14 million. During First Quarter 2015, there was positive economic development of approximately $9 million, which was due primarily to improving collateral performance during the quarter.
Manufactured Housing
The Company insures or reinsures a total of $215 million net par of securities backed by manufactured housing loans, of which $155 million is rated BIG. The Company has expected loss to be paid of $25 million as of March 31, 2015. The economic loss development during First Quarter 2015 was immaterial.
Student Loan Transactions
The Company has insured or reinsured $2.5 billion net par of student loan securitizations, of which $1.8 billion was issued by private issuers and classified as asset-backed and $0.7 billion was issued by public authorities and classified as public finance. Of these amounts, $193 million and $90 million, respectively, are rated BIG. The Company is projecting approximately $75 million of net expected loss to be paid in these portfolios. In general, the losses are due to: (i) the poor credit performance of private student loan collateral and high loss severities, or (ii) high interest rates on auction rate securities with respect to which the auctions have failed. The positive economic development during First Quarter 2015 was approximately $8 million, which was due to a partial commutation by the underlying insurer.
Recovery Litigation
RMBS Transactions
In November 2014, AGM and its affiliate AGC reached a confidential settlement with DLJ Mortgage Capital, Inc., Credit Suisse First Boston Mortgage Securities Corp. and Credit Suisse Securities (USA) LLC to resolve a lawsuit relating to six first lien U.S. RMBS transactions. AGM and AGC sought damages for alleged breaches of representations and warranties in respect of the underlying loans in these transactions, and failure to cure or repurchase defective loans identified by AGM and AGC.  On November 25, 2014, the parties filed a joint stipulation discontinuing the lawsuit with prejudice.  However, on November 20, 2014, U.S. Bank National Association, as trustee for the transactions, had filed a motion to intervene as a plaintiff in the lawsuit.  On November 26, 2014, the trustee submitted a letter stating that the joint stipulation is ineffective and that the lawsuit may be discontinued only by court order, and requesting an opportunity to review and potentially oppose the settlement.  On March 5, 2015 the Court denied the motion to intervene.
Triple-X Life Insurance Transactions
In December 2008, AGUK filed an action against J.P. Morgan Investment Management Inc. (“JPMIM”), the investment manager in the Orkney Re II transaction, in the Supreme Court of the State of New York alleging that JPMIM engaged in breaches of fiduciary duty, gross negligence and breaches of contract based upon its handling of the investments of Orkney Re II. After AGUK’s claims were dismissed with prejudice in January 2010, AGUK was successful in its subsequent motions and appeals and, as of December 2011, all of AGUK’s claims for breaches of fiduciary duty, gross negligence and contract were reinstated in full. Separately, at the trial court level, discovery is ongoing.
Public Finance Transactions
On November 1, 2013, Radian Asset commenced a declaratory judgment action in the U.S. District Court for the Southern District of Mississippi against Madison County, Mississippi (the "County") and the Parkway East Public Improvement District (the "District") to establish its rights under a contribution agreement from the County supporting the District’s Special Assessment Bonds, Series 2005, insured by Radian Asset, with $21.8 million outstanding on March 31, 2015. The County maintains that its payment obligation is limited to two years of annual debt service, while Radian Asset contends no such limitation applies. On April 20, 2015, the Court issued an order addressing cross-motions for partial summary judgment filed by Radian Asset and the County, and denied the County's motion for summary judgment that its payment obligation lasts only two years. On May 1, 2015, AGC paid its first claim on the District's bonds.

Financial_Guaranty_Insurance_L

Financial Guaranty Insurance Losses	3 Months Ended
	Mar. 31, 2015
Insurance [Abstract]
Financial Guaranty Insurance Losses	Financial Guaranty Insurance Losses
	Insurance Contracts' Loss Information
	The following table provides balance sheet information on loss and LAE reserves and salvage and subrogation recoverable, net of reinsurance. The Company used weighted average risk-free rates for U.S. dollar denominated financial guaranty insurance obligations that ranged from 0.0% to 2.89% as of March 31, 2015 and 0.0% to 2.95% as of December 31, 2014. Financial guaranty insurance expected LAE reserve was $10 million as of March 31, 2015 and $12 million as of December 31, 2014.
	Loss and LAE Reserve and Salvage and Subrogation Recoverable
	Net of Reinsurance
	Insurance Contracts
		As of March 31, 2015									As of December 31, 2014
		Loss and			Salvage and			Net Reserve (Recoverable)			Loss and			Salvage and			Net Reserve (Recoverable)
		LAE			Subrogation						LAE			Subrogation
		Reserve, net			Recoverable, net						Reserve, net			Recoverable, net
		(in millions)
	Public Finance:
	U.S. public finance	$	253		$	8		$	245		$	243		$	8		$	235
	Non-U.S. public finance	28			—			28			30			—			30
	Public Finance	281			8			273			273			8			265
	Structured Finance:
	U.S. RMBS:
	First lien:
	Prime first lien	2			—			2			2			—			2
	Alt-A first lien	80			—			80			87			—			87
	Option ARM	24			42			(18		)	28			40			(12		)
	Subprime	159			6			153			166			8			158
	First lien	265			48			217			283			48			235
	Second lien:
	Closed-end second lien	5			37			(32		)	4			39			(35		)
	HELOCs	2			29			(27		)	3			39			(36		)
	Second lien	7			66			(59		)	7			78			(71		)
	Total U.S. RMBS	272			114			158			290			126			164
	Triple-X life insurance transactions	144			—			144			140			—			140
	TruPS	—			—			—			0			—			0
	Other structured finance	90			—			90			96			2			94
	Structured Finance	506			114			392			526			128			398
	Financial guaranty	787			122			665			799			136			663
	Other recoverables	—			7			(7		)	—			13			(13		)
	Subtotal	787			129			658			799			149			650
	Effect of consolidating FG VIEs	(78		)	(1		)	(77		)	(80		)	(1		)	(79		)
	Subtotal	709			128			581			719			148			571
	Other	1			—			1			2			6			(4		)
	Total (1)	$	710		$	128		$	582		$	721		$	154		$	567
	____________________
	-1	See “Components of Net Reserves (Salvage)” table for loss and LAE reserve and salvage and subrogation recoverable components.
	The following table reconciles the reported gross and ceded reserve and salvage and subrogation amount to the financial guaranty net reserves (salvage) in the financial guaranty BIG transaction loss summary tables.
	Components of Net Reserves (Salvage)
	Insurance Contracts
		As of			As of
		31-Mar-15			31-Dec-14
		(in millions)
	Loss and LAE reserve	$	787		$	799
	Reinsurance recoverable on unpaid losses	(77		)	(78		)
	Loss and LAE reserve, net	710			721
	Salvage and subrogation recoverable	(128		)	(151		)
	Salvage and subrogation payable(1)	7			10
	Other recoverables	(7		)	(13		)
	Salvage and subrogation recoverable, net and other recoverable	(128		)	(154		)
	Subtotal	582			567
	Less: other (non-financial guaranty business)	1			(4		)
	Net reserves (salvage) - financial guaranty	$	581		$	571
	____________________
	-1	Recorded as a component of reinsurance balances payable.
	Balance Sheet Classification of
	Net Expected Recoveries for Breaches of R&W
	Insurance Contracts
		As of March 31, 2015									As of December 31, 2014
		For all			Effect of			Reported on			For all			Effect of			Reported on
Financial			Consolidating			Balance Sheet(1)			Financial			Consolidating			Balance Sheet(1)
Guaranty			FG VIEs						Guaranty			FG VIEs
Insurance									Insurance
Contracts									Contracts
	(in millions)
Salvage and subrogation recoverable, net	$	2		$	—		$	2		$	20		$	—		$	20
Loss and LAE reserve, net	146			(8		)	138			185			(8		)	177
____________________
-1	The remaining benefit for R&W is either recorded at fair value in FG VIE assets, or not recorded on the balance sheet until the total loss, net of R&W, exceeds unearned premium reserve.
The table below provides a reconciliation of net expected loss to be paid to net expected loss to be expensed. Expected loss to be paid differs from expected loss to be expensed due to: (1) the contra-paid which represent the claim payments made and recoveries received that have not yet been recognized in the statement of operations, (2) salvage and subrogation recoverable for transactions that are in a net recovery position where the Company has not yet received recoveries on claims previously paid (having the effect of reducing net expected loss to be paid by the amount of the previously paid claim and the expected recovery), but will have no future income effect (because the previously paid claims and the corresponding recovery of those claims will offset in income in future periods), and (3) loss reserves that have already been established (and therefore expensed but not yet paid).
Reconciliation of Net Expected Loss to be Paid and
Net Expected Loss to be Expensed
Financial Guaranty Insurance Contracts
	As of
	31-Mar-15
	(in millions)
Net expected loss to be paid	$	1,111
Less: net expected loss to be paid for FG VIEs	122
Total	989
Contra-paid, net	(93		)
Salvage and subrogation recoverable, net of reinsurance	121
Loss and LAE reserve, net of reinsurance	(709		)
Other recoveries	7
Net expected loss to be expensed (present value) (1)	$	315
____________________
-1	Excludes $86 million as of March 31, 2015, related to consolidated FG VIEs.
The following table provides a schedule of the expected timing of net expected losses to be expensed. The amount and timing of actual loss and LAE may differ from the estimates shown below due to factors such as refundings, accelerations, commutations, changes in expected lives and updates to loss estimates. This table excludes amounts related to FG VIEs, which are eliminated in consolidation.
Net Expected Loss to be Expensed
Financial Guaranty Insurance Contracts
	As of
	31-Mar-15
	(in millions)
2015 (April 1 – June 30)	$	7
2015 (July 1 – September 30)	9
2015 (October 1 – December 31)	11
Subtotal 2015	27
2016	36
2017	27
2018	25
2019	23
2020-2024	77
2025-2029	45
2030-2034	34
After 2034	21
Net expected loss to be expensed	315
Discount	389
Total expected future loss and LAE	$	704
The following table presents the loss and LAE recorded in the consolidated statements of operations by sector for insurance contracts. Amounts presented are net of reinsurance.
Loss and LAE
Reported on the
Consolidated Statements of Operations
	First Quarter
	2015			2014
	(in millions)
Public Finance:
U.S. public finance	$	13		$	26
Non-U.S. public finance	5			1
Public finance	18			27
Structured Finance:
U.S. RMBS:
First lien:
Prime first lien	0			0
Alt-A first lien	(2		)	7
Option ARM	(1		)	(8		)
Subprime	0			(8		)
First lien	(3		)	(9		)
Second lien:
Closed-end second lien	1			—
HELOCs	9			8
Second lien	10			8
Total U.S. RMBS	7			(1		)
Triple-X life insurance transactions	6			13
TruPS	(1		)	(1		)
Other structured finance	(6		)	3
Structured finance	6			14
Subtotal	24			41
Other	(1		)	(1		)
Loss and LAE on insurance contracts before FG VIE consolidation	23			40
Effect of consolidating FG VIEs	(5		)	1
Loss and LAE	$	18		$	41
The following table provides information on financial guaranty insurance contracts categorized as BIG.
Financial Guaranty Insurance
BIG Transaction Loss Summary
As of March 31, 2015
	BIG  Categories
	BIG 1						BIG 2						BIG 3						Total			Effect of			Total
																			BIG, Net			Consolidating
	Gross			Ceded			Gross			Ceded			Gross			Ceded						FG VIEs
	(dollars in millions)
Number of risks(1)	164			(61		)	73			(15		)	119			(38		)	356			—			356
Remaining weighted-average contract period (in years)	9.8			7.2			8.7			7.2			9.9			7.3			10.1			—			10.1
Outstanding exposure:
Principal	$	11,993		$	(2,106	)	$	2,701		$	(356	)	$	2,847		$	(142	)	$	14,937		$	—		$	14,937
Interest	6,082			(792		)	1,262			(127		)	1,013			(45		)	7,393			—			7,393
Total(2)	$	18,075		$	(2,898	)	$	3,963		$	(483	)	$	3,860		$	(187	)	$	22,330		$	—		$	22,330
Expected cash outflows (inflows)	$	1,655		$	(616	)	$	759		$	(84	)	$	1,721		$	(91	)	$	3,344		$	(343	)	$	3,001
Potential recoveries
Undiscounted R&W	(1		)	(1		)	(47		)	2			(133		)	7			(173		)	8			(165		)
Other(3)	(1,583		)	600			(271		)	18			(449		)	47			(1,638		)	180			(1,458		)
Total potential recoveries	(1,584		)	599			(318		)	20			(582		)	54			(1,811		)	188			(1,623		)
Subtotal	71			(17		)	441			(64		)	1,139			(37		)	1,533			(155		)	1,378
Discount	(7		)	0			(96		)	10			(336		)	7			(422		)	33			(389		)
Present value of expected cash flows	$	64		$	(17	)	$	345		$	(54	)	$	803		$	(30	)	$	1,111		$	(122	)	$	989
Deferred premium revenue	$	402		$	(75	)	$	104		$	(6	)	$	268		$	(25	)	$	668		$	(111	)	$	557
Reserves (salvage)(4)	$	(10	)	$	(7	)	$	269		$	(52	)	$	468		$	(10	)	$	658		$	(77	)	$	581
Financial Guaranty Insurance
BIG Transaction Loss Summary
As of December 31, 2014
	BIG Categories
	BIG 1						BIG 2						BIG 3						Total			Effect of			Total
																			BIG, Net			Consolidating
	Gross			Ceded			Gross			Ceded			Gross			Ceded						FG VIEs
	(dollars in millions)
Number of risks(1)	164			(59		)	75			(15		)	119			(38		)	358			—			358
Remaining weighted-average contract period (in years)	9.9			7.4			10.1			8.9			9.6			6.9			10.3			—			10.3
Outstanding exposure:
Principal	$	12,358		$	(2,163	)	$	2,421		$	(286	)	$	3,067		$	(175	)	$	15,222		$	—		$	15,222
Interest	6,350			(838		)	1,274			(121		)	1,034			(48		)	7,651			—			7,651
Total(2)	$	18,708		$	(3,001	)	$	3,695		$	(407	)	$	4,101		$	(223	)	$	22,873		$	—		$	22,873
Expected cash outflows (inflows)	$	1,762		$	(626	)	$	763		$	(77	)	$	1,716		$	(75	)	$	3,463		$	(345	)	$	3,118
Potential recoveries
Undiscounted R&W	(39		)	0			(48		)	2			(171		)	9			(247		)	8			(239		)
Other(3)	(1,687		)	608			(206		)	5			(404		)	30			(1,654		)	177			(1,477		)
Total potential recoveries	(1,726		)	608			(254		)	7			(575		)	39			(1,901		)	185			(1,716		)
Subtotal	36			(18		)	509			(70		)	1,141			(36		)	1,562			(160		)	1,402
Discount	3			0			(117		)	11			(353		)	9			(447		)	34			(413		)
Present value of expected cash flows	$	39		$	(18	)	$	392		$	(59	)	$	788		$	(27	)	$	1,115		$	(126	)	$	989
Deferred premium revenue	$	378		$	(70	)	$	119		$	(6	)	$	312		$	(33	)	$	700		$	(116	)	$	584
Reserves (salvage)(4)	$	(42	)	$	(5	)	$	278		$	(53	)	$	482		$	(10	)	$	650		$	(79	)	$	571
____________________
-1	A risk represents the aggregate of the financial guaranty policies that share the same revenue source for purposes of making Debt Service payments. The ceded number of risks represents the number of risks for which the Company ceded a portion of its exposure.
-2	Includes BIG amounts related to FG VIEs.
-3	Includes excess spread and draws on HELOCs.
-4	See table “Components of net reserves (salvage).”
Ratings Impact on Financial Guaranty Business
A downgrade of one of the Company’s insurance subsidiaries may result in increased claims under financial guaranties issued by the Company, if the insured obligors were unable to pay.
For example, AGM has issued financial guaranty insurance policies in respect of the obligations of municipal obligors under interest rate swaps. Under the swaps, AGM insures periodic payments owed by the municipal obligors to the bank counterparties. Under certain of the swaps, AGM also insures termination payments that may be owed by the municipal obligors to the bank counterparties. If (i) AGM has been downgraded below the rating trigger set forth in a swap under which it has insured the termination payment, which rating trigger varies on a transaction by transaction basis; (ii) the municipal obligor has the right to cure by, but has failed in, posting collateral, replacing AGM or otherwise curing the downgrade of AGM; (iii) the transaction documents include as a condition that an event of default or termination event with respect to the municipal obligor has occurred, such as the rating of the municipal obligor being downgraded past a specified level, and such condition has been met; (iv) the bank counterparty has elected to terminate the swap; (v) a termination payment is payable by the municipal obligor; and (vi) the municipal obligor has failed to make the termination payment payable by it, then AGM would be required to pay the termination payment due by the municipal obligor, in an amount not to exceed the policy limit set forth in the financial guaranty insurance policy. At AGM's current financial strength ratings, if the conditions giving rise to the obligation of AGM to make a termination payment under the swap termination policies were all satisfied, then AGM could pay claims in an amount not exceeding approximately $163 million in respect of such termination payments. Taking into consideration whether the rating of the municipal obligor is below any applicable specified trigger, if the financial strength ratings of AGM were further downgraded below "A" by S&P or below "A2" by Moody's, and the conditions giving rise to the obligation of AGM to make a payment under the swap policies were all satisfied, then AGM could pay claims in an additional amount not exceeding approximately $416 million in respect of such termination payments.
As another example, with respect to variable rate demand obligations ("VRDOs") for which a bank has agreed to provide a liquidity facility, a downgrade of AGM or AGC may provide the bank with the right to give notice to bondholders that the bank will terminate the liquidity facility, causing the bondholders to tender their bonds to the bank. Bonds held by the bank accrue interest at a “bank bond rate” that is higher than the rate otherwise borne by the bond (typically the prime rate plus 2.00% — 3.00%, and capped at the lesser of 25% and the maximum legal limit). In the event the bank holds such bonds for longer than a specified period of time, usually 90-180 days, the bank has the right to demand accelerated repayment of bond principal, usually through payment of equal installments over a period of not less than five years. In the event that a municipal obligor is unable to pay interest accruing at the bank bond rate or to pay principal during the shortened amortization period, a claim could be submitted to AGM or AGC under its financial guaranty policy. As of March 31, 2015, AGM and AGC had insured approximately $5.9 billion net par of VRDOs, of which approximately $0.3 billion of net par constituted VRDOs issued by municipal obligors rated BBB- or lower pursuant to the Company’s internal rating. The specific terms relating to the rating levels that trigger the bank’s termination right, and whether it is triggered by a downgrade by one rating agency or a downgrade by all rating agencies then rating the insurer, vary depending on the transaction.
In addition, AGM may be required to pay claims in respect of AGMH’s former financial products business if Dexia SA and its affiliates, from which the Company had purchased AGMH and its subsidiaries, do not comply with their obligations following a downgrade of the financial strength rating of AGM. Most of the guaranteed investment contracts ("GICs") insured by AGM allow the GIC holder to terminate the GIC and withdraw the funds in the event of a downgrade of AGM below A3 or A-, with no right of the GIC issuer to avoid such withdrawal by posting collateral or otherwise enhancing its credit. Each GIC contract stipulates the thresholds below which the GIC issuer must post eligible collateral, along with the types of securities eligible for posting and the collateralization percentage applicable to each security type. These collateralization percentages range from 100% of the GIC balance for cash posted as collateral to, typically, 108% for asset-backed securities. If the entire aggregate accreted GIC balance of approximately $2.1 billion as of March 31, 2015 were terminated, the assets of the GIC issuers (which had an aggregate accreted principal of approximately $3.3 billion and an aggregate market value of approximately $3.2 billion) would be sufficient to fund the withdrawal of the GIC funds.

Fair_Value_Measurement

Fair Value Measurement	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurement	Fair Value Measurement
	The Company carries a significant portion of its assets and liabilities at fair value. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (i.e., exit price). The price represents the price available in the principal market for the asset or liability. If there is no principal market, then the price is based on a hypothetical market that maximizes the value received for an asset or minimizes the amount paid for a liability (i.e., the most advantageous market).
	Fair value is based on quoted market prices, where available. If listed prices or quotes are not available, fair value is based on either internally developed models that primarily use, as inputs, market-based or independently sourced market parameters, including but not limited to yield curves, interest rates and debt prices or with the assistance of an independent third-party using a discounted cash flow approach and the third party’s proprietary pricing models. In addition to market information, models also incorporate transaction details, such as maturity of the instrument and contractual features designed to reduce the Company’s credit exposure, such as collateral rights as applicable.
	Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments include amounts to reflect counterparty credit quality, the Company’s creditworthiness and constraints on liquidity. As markets and products develop and the pricing for certain products becomes more or less transparent, the Company may refine its methodologies and assumptions. During First Quarter 2015, no changes were made to the Company’s valuation models that had or are expected to have, a material impact on the Company’s consolidated balance sheets or statements of operations and comprehensive income.
	The Company’s methods for calculating fair value produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. The use of different methodologies or assumptions to determine fair value of certain financial instruments could result in a different estimate of fair value at the reporting date.
	The fair value hierarchy is determined based on whether the inputs to valuation techniques used to measure fair value are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect Company estimates of market assumptions. The fair value hierarchy prioritizes model inputs into three broad levels as follows, with Level 1 being the highest and Level 3 the lowest. An asset or liability’s categorization within the fair value hierarchy is based on the lowest level of significant input to its valuation.
	Level 1—Quoted prices for identical instruments in active markets. The Company generally defines an active market as a market in which trading occurs at significant volumes. Active markets generally are more liquid and have a lower bid-ask spread than an inactive market.
	Level 2—Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and observable inputs other than quoted prices, such as interest rates or yield curves and other inputs derived from or corroborated by observable market inputs.
	Level 3—Model derived valuations in which one or more significant inputs or significant value drivers are unobservable. Financial instruments are considered Level 3 when their values are determined using pricing models, discounted cash flow methodologies or similar techniques and at least one significant model assumption or input is unobservable. Level 3 financial instruments also include those for which the determination of fair value requires significant management judgment or estimation.
	Transfers between Levels 1, 2 and 3 are recognized at the end of the period when the transfer occurs. The Company reviews the classification between Levels 1, 2 and 3 quarterly to determine whether a transfer is necessary. During the periods presented, there were no transfers between Level 1, 2 and 3.
	Measured and Carried at Fair Value
	Fixed-Maturity Securities and Short-Term Investments
	The fair value of bonds in the investment portfolio is generally based on prices received from third party pricing services or alternative pricing sources with reasonable levels of price transparency. The pricing services prepare estimates of fair value measurements using their pricing models, which include available relevant market information, benchmark curves, benchmarking of like securities, and sector groupings. Additional valuation factors that can be taken into account are nominal spreads and liquidity adjustments. The pricing services evaluate each asset class based on relevant market and credit information, perceived market movements, and sector news. The market inputs used in the pricing evaluation include: benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, reference data and industry and economic events. Benchmark yields have in many cases taken priority over reported trades for securities that trade less frequently or those that are distressed trades, and therefore may not be indicative of the market. The extent of the use of each input is dependent on the asset class and the market conditions. Given the asset class, the priority of the use of inputs may change or some market inputs may not be relevant. Additionally, the valuation of fixed-maturity investments is more subjective when markets are less liquid due to the lack of market based inputs, which may increase the potential that the estimated fair value of an investment is not reflective of the price at which an actual transaction would occur.
	Short-term investments, that are traded in active markets, are classified within Level 1 in the fair value hierarchy and are based on quoted market prices. Securities such as discount notes are classified within Level 2 because these securities are typically not actively traded due to their approaching maturity and, as such, their cost approximates fair value.
	Prices determined based on models where at least one significant model assumption or input is unobservable, are considered to be Level 3 in the fair value hierarchy. As of March 31, 2015, the Company used models to price 34 fixed-maturity securities (which were purchased for loss mitigation or other management purposes), which was 6.8% or $696 million of the Company’s fixed-maturity securities and short-term investments at fair value. Certain Level 3 securities were priced with the assistance of an independent third-party. The pricing is based on a discounted cash flow approach using the third-party’s proprietary pricing models. The models use inputs such as projected prepayment speeds;  severity assumptions; recovery lag assumptions; estimated default rates (determined on the basis of an analysis of collateral attributes, historical collateral performance, borrower profiles and other features relevant to the evaluation of collateral credit quality); home price depreciation/appreciation rates based on macroeconomic forecasts and recent trading activity. The yield used to discount the projected cash flows is determined by reviewing various attributes of the bond including collateral type, weighted average life, sensitivity to losses, vintage, and convexity, in conjunction with market data on comparable securities. Significant changes to any of these inputs could materially change the expected timing of cash flows within these securities which is a significant factor in determining the fair value of the securities.
	Other Invested Assets
	As of March 31, 2015 and December 31, 2014, other invested assets include investments carried and measured at fair value on a recurring basis of $102 million and $95 million, respectively, and include primarily investments in the global property catastrophe risk market and investment in a fund that invests primarily in senior loans and bonds. Both of these investments were classified as Level 3. Other invested assets also include fixed-maturity securities classified as trading carried as Level 2.
	Other Assets
	Committed Capital Securities
	The fair value of committed capital securities ("CCS"), which is recorded in other assets on the consolidated balance sheets, represents the difference between the present value of remaining expected put option premium payments under AGC’s CCS (the “AGC CCS”) and AGM’s Committed Preferred Trust Securities (the “AGM CPS”) agreements, and the estimated present value that the Company would hypothetically have to pay currently for a comparable security (see Note 15, Long Term Debt and Credit Facilities). The AGC CCS and AGM CPS are carried at fair value with changes in fair value recorded on the consolidated statement of operations. The estimated current cost of the Company’s CCS is based on several factors, including broker-dealer quotes for the outstanding securities, AGM and AGC CDS spreads, the U.S. dollar forward swap curve, London Interbank Offered Rate ("LIBOR") curve projections and the term the securities are estimated to remain outstanding.
	Supplemental Executive Retirement Plans
	The Company classifies the fair value measurement of the assets of the Company's various supplemental executive retirement plans as either Level 1 or Level 2. The fair value of these assets is valued based on the observable published daily values of the underlying mutual fund included in the aforementioned plans (Level 1) or based upon the net asset value of the funds if a published daily value is not available (Level 2). The net asset values are based on observable information.
	Financial Guaranty Contracts Accounted for as Credit Derivatives
	The Company’s credit derivatives consist primarily of insured CDS contracts, and also include interest rate swaps that fall under derivative accounting standards requiring fair value accounting through the statement of operations. The Company does not enter into CDS with the intent to trade these contracts and the Company may not unilaterally terminate a CDS contract absent an event of default or termination event that entitles the Company to terminate; however, the Company has mutually agreed with various counterparties to terminate certain CDS transactions. Such terminations generally are not completed at fair value but instead for an amount that approximates the present value of future premiums or for an amount negotiated as part of an R&W settlement.
	The terms of the Company’s CDS contracts differ from more standardized credit derivative contracts sold by companies outside the financial guaranty industry. The non-standard terms include the absence of collateral support agreements or immediate settlement provisions. In addition, the Company employs relatively high attachment points and does not exit derivatives it sells or purchases for credit protection purposes, except under specific circumstances such as mutual agreements with counterparties. Management considers the non-standard terms of its credit derivative contracts in determining the fair value of these contracts.
	Due to the lack of quoted prices and other observable inputs for its instruments or for similar instruments, the Company determines the fair value of its credit derivative contracts primarily through internally developed, proprietary models that use both observable and unobservable market data inputs to derive an estimate of the fair value of the Company's contracts in its principal markets (see "Assumptions and Inputs"). There is no established market where financial guaranty insured credit derivatives are actively traded, therefore, management has determined that the exit market for the Company’s credit derivatives is a hypothetical one based on its entry market. Management has tracked the historical pricing of the Company’s deals to establish historical price points in the hypothetical market that are used in the fair value calculation. These contracts are classified as Level 3 in the fair value hierarchy since there is reliance on at least one unobservable input deemed significant to the valuation model, most importantly the Company’s estimate of the value of the non-standard terms and conditions of its credit derivative contracts and of the Company’s current credit standing.
	The Company’s models and the related assumptions are continuously reevaluated by management and enhanced, as appropriate, based upon improvements in modeling techniques and availability of more timely and relevant market information.
	The fair value of the Company’s credit derivative contracts represents the difference between the present value of remaining premiums the Company expects to receive or pay and the estimated present value of premiums that a financial guarantor of comparable credit-worthiness would hypothetically charge or pay at the reporting date for the same protection. The fair value of the Company’s credit derivatives depends on a number of factors, including notional amount of the contract, expected term, credit spreads, changes in interest rates, the credit ratings of referenced entities, the Company’s own credit risk and remaining contractual cash flows. The expected remaining contractual premium cash flows are the most readily observable inputs since they are based on the CDS contractual terms. Credit spreads capture the effect of recovery rates and performance of underlying assets of these contracts, among other factors. Consistent with previous years, market conditions at March 31, 2015 were such that market prices of the Company’s CDS contracts were not available.
	Management considers factors such as current prices charged for similar agreements, when available, performance of underlying assets, life of the instrument, and the nature and extent of activity in the financial guaranty credit derivative marketplace. The assumptions that management uses to determine the fair value may change in the future due to market conditions. Due to the inherent uncertainties of the assumptions used in the valuation models, actual experience may differ from the estimates reflected in the Company’s consolidated financial statements and the differences may be material.
	Assumptions and Inputs
	The various inputs and assumptions that are key to the establishment of the Company’s fair value for CDS contracts are as follows:
	•Gross spread.
	•The allocation of gross spread among:
	◦	the profit the originator, usually an investment bank, realizes for putting the deal together and funding the transaction (“bank profit”);
	◦	premiums paid to the Company for the Company’s credit protection provided (“net spread”); and
	◦	the cost of CDS protection purchased by the originator to hedge their counterparty credit risk exposure to the Company (“hedge cost”).
	•The weighted average life which is based on Debt Service schedules.
	The rates used to discount future expected premium cash flows ranged from 0.18% to 2.32% at March 31, 2015 and 0.26% to 2.70% at December 31, 2014.
	The Company obtains gross spreads on its outstanding contracts from market data sources published by third parties (e.g., dealer spread tables for the collateral similar to assets within the Company’s transactions), as well as collateral-specific spreads provided by trustees or obtained from market sources. If observable market credit spreads are not available or reliable for the underlying reference obligations, then market indices are used that most closely resemble the underlying reference obligations, considering asset class, credit quality rating and maturity of the underlying reference obligations. These indices are adjusted to reflect the non-standard terms of the Company’s CDS contracts. Market sources determine credit spreads by reviewing new issuance pricing for specific asset classes and receiving price quotes from their trading desks for the specific asset in question. Management validates these quotes by cross-referencing quotes received from one market source against quotes received from another market source to ensure reasonableness. In addition, the Company compares the relative change in price quotes received from one quarter to another, with the relative change experienced by published market indices for a specific asset class. Collateral specific spreads obtained from third-party, independent market sources are un-published spread quotes from market participants or market traders who are not trustees. Management obtains this information as the result of direct communication with these sources as part of the valuation process.
	With respect to CDS transactions for which there is an expected claim payment within the next twelve months, the allocation of gross spread reflects a higher allocation to the cost of credit rather than the bank profit component. In the current market, it is assumed that a bank would be willing to accept a lower profit on distressed transactions in order to remove these transactions from its financial statements.
	The following spread hierarchy is utilized in determining which source of gross spread to use, with the rule being to use CDS spreads where available. If not available, CDS spreads are either interpolated or extrapolated based on similar transactions or market indices.
	•	Actual collateral specific credit spreads (if up-to-date and reliable market-based spreads are available).
	•	Deals priced or closed during a specific quarter within a specific asset class and specific rating. There were no deals closed during the period presented.
	•	Credit spreads interpolated based upon market indices.
	•	Credit spreads provided by the counterparty of the CDS.
	•	Credit spreads extrapolated based upon transactions of similar asset classes, similar ratings, and similar time to maturity.
	Information by Credit Spread Type (1)
		As of			As of
		31-Mar-15			31-Dec-14
	Based on actual collateral specific spreads	9	%		9	%
	Based on market indices	81	%		82	%
	Provided by the CDS counterparty	10	%		9	%
	Total	100	%		100	%
	____________________
	(1)    Based on par.
	Over time the data inputs can change as new sources become available or existing sources are discontinued or are no longer considered to be the most appropriate. It is the Company’s objective to move to higher levels on the hierarchy whenever possible, but it is sometimes necessary to move to lower priority inputs because of discontinued data sources or management’s assessment that the higher priority inputs are no longer considered to be representative of market spreads for a given type of collateral. This can happen, for example, if transaction volume changes such that a previously used spread index is no longer viewed as being reflective of current market levels.
	The Company interpolates a curve based on the historical relationship between the premium the Company receives when a credit derivative is closed to the daily closing price of the market index related to the specific asset class and rating of the deal. This curve indicates expected credit spreads at each indicative level on the related market index. For transactions with unique terms or characteristics where no price quotes are available, management extrapolates credit spreads based on a similar transaction for which the Company has received a spread quote from one of the first three sources within the Company’s spread hierarchy. This alternative transaction will be within the same asset class, have similar underlying assets, similar credit ratings, and similar time to maturity. The Company then calculates the percentage of relative spread change quarter over quarter for the alternative transaction. This percentage change is then applied to the historical credit spread of the transaction for which no price quote was received in order to calculate the transactions’ current spread. Counterparties determine credit spreads by reviewing new issuance pricing for specific asset classes and receiving price quotes from their trading desks for the specific asset in question. These quotes are validated by cross-referencing quotes received from one market source with those quotes received from another market source to ensure reasonableness.
	The premium the Company receives is referred to as the “net spread.” The Company’s pricing model takes into account not only how credit spreads on risks that it assumes affect pricing, but also how the Company’s own credit spread affects the pricing of its deals. The Company’s own credit risk is factored into the determination of net spread based on the impact of changes in the quoted market price for credit protection bought on the Company, as reflected by quoted market prices on CDS referencing AGC or AGM. For credit spreads on the Company’s name the Company obtains the quoted price of CDS contracts traded on AGC and AGM from market data sources published by third parties. The cost to acquire CDS protection referencing AGC or AGM affects the amount of spread on CDS deals that the Company retains and, hence, their fair value. As the cost to acquire CDS protection referencing AGC or AGM increases, the amount of premium the Company retains on a deal generally decreases. As the cost to acquire CDS protection referencing AGC or AGM decreases, the amount of premium the Company retains on a deal generally increases. In the Company’s valuation model, the premium the Company captures is not permitted to go below the minimum rate that the Company would currently charge to assume similar risks. This assumption can have the effect of mitigating the amount of unrealized gains that are recognized on certain CDS contracts. Given the current market conditions and the Company’s own credit spreads, approximately 20% and 21% based on number of deals, of the Company's CDS contracts are fair valued using this minimum premium as of March 31, 2015 and December 31, 2014, respectively. The percentage of deals that price using the minimum premiums fluctuates due to changes in AGM's and AGC's credit spreads. In general when AGM's and AGC's credit spreads narrow, the cost to hedge AGM's and AGC's name declines and more transactions price above previously established floor levels. Meanwhile, when AGM's and AGC's credit spreads widen, the cost to hedge AGM's and AGC's name increases causing more transactions to price at previously established floor levels. The Company corroborates the assumptions in its fair value model, including the portion of exposure to AGC and AGM hedged by its counterparties, with independent third parties each reporting period. The current level of AGC’s and AGM’s own credit spread has resulted in the bank or deal originator hedging a significant portion of its exposure to AGC and AGM. This reduces the amount of contractual cash flows AGC and AGM can capture as premium for selling its protection.
	The amount of premium a financial guaranty insurance market participant can demand is inversely related to the cost of credit protection on the insurance company as measured by market credit spreads assuming all other assumptions remain constant. This is because the buyers of credit protection typically hedge a portion of their risk to the financial guarantor, due to the fact that the contractual terms of the Company's contracts typically do not require the posting of collateral by the guarantor. The extent of the hedge depends on the types of instruments insured and the current market conditions.
	A fair value resulting in a credit derivative asset on protection sold is the result of contractual cash inflows on in-force deals in excess of what a hypothetical financial guarantor could receive if it sold protection on the same risk as of the reporting date. If the Company were able to freely exchange these contracts (i.e., assuming its contracts did not contain proscriptions on transfer and there was a viable exchange market), it would be able to realize a gain representing the difference between the higher contractual premiums to which it is entitled and the current market premiums for a similar contract. The Company determines the fair value of its CDS contracts by applying the difference between the current net spread and the contractual net spread for the remaining duration of each contract to the notional value of its CDS contracts and taking the present value of such amounts discounted at the corresponding LIBOR over the weighted average remaining life of the contract.
	Example
	The following is an example of how changes in gross spreads, the Company’s own credit spread and the cost to buy protection on the Company affect the amount of premium the Company can demand for its credit protection. The assumptions used in these examples are hypothetical amounts. Scenario 1 represents the market conditions in effect on the transaction date and Scenario 2 represents market conditions at a subsequent reporting date.
		Scenario 1						Scenario 2
		bps			% of Total			bps			% of Total
Original gross spread/cash bond price (in bps)	185						500
Bank profit (in bps)	115			62	%		50			10	%
Hedge cost (in bps)	30			16	%		440			88	%
The premium the Company receives per annum (in bps)	40			22	%		10			2	%
In Scenario 1, the gross spread is 185 basis points. The bank or deal originator captures 115 basis points of the original gross spread and hedges 10% of its exposure to AGC, when the CDS spread on AGC was 300 basis points (300 basis points × 10% =/font>30 basis points). Under this scenario the Company receives premium of 40 basis points, or 22% of the gross spread.
In Scenario 2, the gross spread is 500 basis points. The bank or deal originator captures 50 basis points of the original gross spread and hedges 25% of its exposure to AGC, when the CDS spread on AGC was 1,760 basis points (1,760 basis points × 25% =/font>440 basis points). Under this scenario the Company would receive premium of 10 basis points, or 2% of the gross spread. Due to the increased cost to hedge AGC’s name, the amount of profit the bank would expect to receive, and the premium the Company would expect to receive decline significantly.
In this example, the contractual cash flows (the Company premium received per annum above) exceed the amount a market participant would require the Company to pay in today’s market to accept its obligations under the CDS contract, thus resulting in an asset.
Strengths and Weaknesses of Model
The Company’s credit derivative valuation model, like any financial model, has certain strengths and weaknesses.
The primary strengths of the Company’s CDS modeling techniques are:
•	The model takes into account the transaction structure and the key drivers of market value. The transaction structure includes par insured, weighted average life, level of subordination and composition of collateral.
•	The model maximizes the use of market-driven inputs whenever they are available. The key inputs to the model are market-based spreads for the collateral, and the credit rating of referenced entities. These are viewed by the Company to be the key parameters that affect fair value of the transaction.
•	The model is a consistent approach to valuing positions. The Company has developed a hierarchy for market-based spread inputs that helps mitigate the degree of subjectivity during periods of high illiquidity.
The primary weaknesses of the Company’s CDS modeling techniques are:
•	There is no exit market or actual exit transactions. Therefore the Company’s exit market is a hypothetical one based on the Company’s entry market.
•	There is a very limited market in which to validate the reasonableness of the fair values developed by the Company’s model.
•	At March 31, 2015 and December 31, 2014, the markets for the inputs to the model were highly illiquid, which impacts their reliability.
•	Due to the non-standard terms under which the Company enters into derivative contracts, the fair value of its credit derivatives may not reflect the same prices observed in an actively traded market of credit derivatives that do not contain terms and conditions similar to those observed in the financial guaranty market.
These contracts were classified as Level 3 in the fair value hierarchy because there is a reliance on at least one unobservable input deemed significant to the valuation model, most significantly the Company's estimate of the value of non-standard terms and conditions of its credit derivative contracts and amount of protection purchased on AGC or AGM's name.
Fair Value Option on FG VIEs’ Assets and Liabilities
The Company elected the fair value option for all the FG VIEs’ assets and liabilities. See Note 9, Consolidated Variable Interest Entities.
The FG VIEs issued securities collateralized by first lien and second lien RMBS as well as loans and receivables. The lowest level input that is significant to the fair value measurement of these assets and liabilities was a Level 3 input (i.e., unobservable), therefore management classified them as Level 3 in the fair value hierarchy. Prices are generally determined with the assistance of an independent third-party. The pricing is based on a discounted cash flow approach and the third-party’s proprietary pricing models. The models to price the FG VIEs’ liabilities used, where appropriate, inputs such as estimated prepayment speeds; market values of the assets that collateralize the securities; estimated default rates (determined on the basis of an analysis of collateral attributes, historical collateral performance, borrower profiles and other features relevant to the evaluation of collateral credit quality); yields implied by market prices for similar securities; house price depreciation/appreciation rates based on macroeconomic forecasts and, for those liabilities insured by the Company, the benefit from the Company’s insurance policy guaranteeing the timely payment of principal and interest, taking into account the timing of the potential default and the Company’s own credit rating. The third-party also utilizes an internal model to determine an appropriate yield at which to discount the cash flows of the security, by factoring in collateral types, weighted-average lives, and other structural attributes specific to the security being priced. The expected yield is further calibrated by utilizing algorithms designed to aggregate market color, received by the third-party, on comparable bonds.
The fair value of the Company’s FG VIE assets is generally sensitive to changes related to estimated prepayment speeds; estimated default rates (determined on the basis of an analysis of collateral attributes such as: historical collateral performance, borrower profiles and other features relevant to the evaluation of collateral credit quality); discount rates implied by market prices for similar securities; and house price depreciation/appreciation rates based on macroeconomic forecasts. Significant changes to some of these inputs could materially change the market value of the FG VIE’s assets and the implied collateral losses within the transaction. In general, the fair value of the FG VIE asset is most sensitive to changes in the projected collateral losses, where an increase in collateral losses typically leads to a decrease in the fair value of FG VIE assets, while a decrease in collateral losses typically leads to an increase in the fair value of FG VIE assets. These factors also directly impact the fair value of the Company’s FG VIE liabilities.
The fair value of the Company’s FG VIE liabilities is also generally sensitive to changes relating to estimated prepayment speeds; market values of the underlying assets; estimated default rates (determined on the basis of an analysis of collateral attributes such as: historical collateral performance, borrower profiles and other features relevant to the evaluation of collateral credit quality); discount rates implied by market prices for similar securities; and house price depreciation/appreciation rates based on macroeconomic forecasts. In addition, the Company’s FG VIE liabilities with recourse are also sensitive to changes in the Company’s implied credit worthiness. Significant changes to any of these inputs could materially change the timing of expected losses within the insured transaction which is a significant factor in determining the implied benefit from the Company’s insurance policy guaranteeing the timely payment of principal and interest for the tranches of debt issued by the FG VIE that is insured by the Company. In general, extending the timing of expected loss payments by the Company into the future typically leads to a decrease in the value of the Company’s insurance and a decrease in the fair value of the Company’s FG VIE liabilities with recourse, while a shortening of the timing of expected loss payments by the Company typically leads to an increase in the value of the Company’s insurance and an increase in the fair value of the Company’s FG VIE liabilities with recourse.
Not Carried at Fair Value
Financial Guaranty Insurance Contracts
The fair value of the Company’s financial guaranty contracts accounted for as insurance was based on management’s estimate of what a similarly rated financial guaranty insurance company would demand to acquire the Company’s in-force book of financial guaranty insurance business. This amount was based on the pricing assumptions management has observed for portfolio transfers and acquisitions that have occurred in the financial guaranty market and included adjustments to the carrying value of unearned premium reserve for stressed losses, ceding commissions and return on capital. The significant inputs were not readily observable. The Company accordingly classified this fair value measurement as Level 3.
Long-Term Debt
The Company’s long-term debt, excluding notes payable, is valued by broker-dealers using third party independent pricing sources and standard market conventions. The market conventions utilize market quotations, market transactions for the Company’s comparable instruments, and to a lesser extent, similar instruments in the broader insurance industry. The fair value measurement was classified as Level 2 in the fair value hierarchy.
The fair value of the notes payable was determined by calculating the present value of the expected cash flows. The Company determines discounted future cash flows using market driven discount rates and a variety of assumptions, including a projection of the LIBOR rate, prepayment and default assumptions, and AGM CDS spreads. The fair value measurement was classified as Level 3 in the fair value hierarchy because there is a reliance on significant unobservable inputs to the valuation model, including the discount rates, prepayment and default assumptions, loss severity and recovery on delinquent loans.
Other Invested Assets
The fair value of the other invested assets was determined by calculating the present value of the expected cash flows. The Company uses a market approach to determine discounted future cash flows using market driven discount rates and a variety of assumptions, including a projection of the LIBOR rate and prepayment and default assumptions. The fair value measurement was classified as Level 3 in the fair value hierarchy because there is a reliance on significant unobservable inputs to the valuation model, including the discount rates, prepayment and default assumptions, loss severity and recovery on delinquent loans.
Other Assets and Other Liabilities
The Company’s other assets and other liabilities consist predominantly of accrued interest, receivables for securities sold and payables for securities purchased, the carrying values of which approximate fair value.
Financial Instruments Carried at Fair Value
Amounts recorded at fair value in the Company’s financial statements are presented in the tables below.
Fair Value Hierarchy of Financial Instruments Carried at Fair Value
As of March 31, 2015
					Fair Value Hierarchy
	Fair Value				Level 1				Level 2				Level 3
	(in millions)
Assets:
Investment portfolio, available-for-sale:
Fixed-maturity securities
Obligations of state and political subdivisions	$	5,458			$	—			$	5,450			$	8
U.S. government and agencies	497				—				497				—
Corporate securities	1,399				—				1,320				79
Mortgage-backed securities:
RMBS	1,185				—				802				383
Commercial mortgage-backed securities ("CMBS")	600				—				600				—
Asset-backed securities	401				—				175				226
Foreign government securities	293				—				293				—
Total fixed-maturity securities	9,833				—				9,137				696
Short-term investments	349				172				177				—
Other invested assets (1)	107				0				26				81
Credit derivative assets	77				—				—				77
FG VIEs’ assets, at fair value (2)	1,495				—				—				1,495
Other assets	84				30				17				37
Total assets carried at fair value	$	11,945			$	202			$	9,357			$	2,386
Liabilities:
Credit derivative liabilities	$	859			$	—			$	—			$	859
FG VIEs’ liabilities with recourse, at fair value	1,278				—				—				1,278
FG VIEs’ liabilities without recourse, at fair value	145				—				—				145
Total liabilities carried at fair value	$	2,282			$	—			$	—			$	2,282
Fair Value Hierarchy of Financial Instruments Carried at Fair Value
As of December 31, 2014
					Fair Value Hierarchy
	Fair Value				Level 1				Level 2				Level 3
	(in millions)
Assets:
Investment portfolio, available-for-sale:
Fixed-maturity securities
Obligations of state and political subdivisions	$	5,795			$	—			$	5,757			$	38
U.S. government and agencies	665				—				665				—
Corporate securities	1,368				—				1,289				79
Mortgage-backed securities:
RMBS	1,285				—				860				425
CMBS	659				—				659				—
Asset-backed securities	417				—				189				228
Foreign government securities	302				—				302				—
Total fixed-maturity securities	10,491				—				9,721				770
Short-term investments	767				359				408				—
Other invested assets (1)	100				0				17				83
Credit derivative assets	68				—				—				68
FG VIEs’ assets, at fair value (2)	1,398				—				—				1,398
Other assets	78				26				17				35
Total assets carried at fair value	$	12,902			$	385			$	10,163			$	2,354
Liabilities:
Credit derivative liabilities	$	963			$	—			$	—			$	963
FG VIEs’ liabilities with recourse, at fair value	1,277				—				—				1,277
FG VIEs’ liabilities without recourse, at fair value	142				—				—				142
Total liabilities carried at fair value	$	2,382			$	—			$	—			$	2,382
____________________
-1	Includes Level 3 mortgage loans that are recorded at fair value on a non-recurring basis.
-2	Exclude restricted cash.
Changes in Level 3 Fair Value Measurements
The table below presents a roll forward of the Company’s Level 3 financial instruments carried at fair value on a recurring basis during First Quarter 2015 and 2014.
Fair Value Level 3 Rollforward
Recurring Basis
First Quarter 2015
	Fixed-Maturity Securities
	Obligations					Corporate Securities					RMBS					Asset-					Other					FG VIEs’					Other					Credit					FG VIEs' Liabilities					FG VIEs’ Liabilities
	of State and															Backed					Invested					Assets at					Assets					Derivative					with					without
	Political															Securities					Assets					Fair										Asset					Recourse,					Recourse,
	Subdivisions																									Value										(Liability),					at Fair					at Fair
																																				net(5)					Value					Value
	(in millions)
Fair value as of December 31, 2014	$	38				$	79				$	425				$	228				$	78				$	1,398				$	35				$	(895	)			$	(1,277	)			$	(142	)
Total pretax realized and unrealized gains/(losses) recorded in:(1)
Net income (loss)	3			(2	)	2			(2	)	9			(2	)	(2		)	(2	)	(4		)	(2	)	23			(3	)	2			(4	)	124			(6	)	93			(3	)	(5		)	(3	)
Other comprehensive income (loss)	(2		)			(2		)			5					1					2					—					—					—					—					—
Purchases	—					—					9					—					—					—					—					—					—					—
Settlements	(31		)	(7	)	—					(65		)			(1		)			0					(30		)			—					(11		)			37					2
FG VIE consolidations	—					—					—					—					—					104					—					—					(131		)			—
FG VIE deconsolidations	—					—					—					—					—					—					—					—					—					—
Fair value as of March 31, 2015	$	8				$	79				$	383				$	226				$	76				$	1,495				$	37				$	(782	)			$	(1,278	)			$	(145	)
Change in unrealized gains/(losses) related to financial instruments held as of March 31, 2015	$	0				$	(2	)			$	7				$	1				$	2				$	34				$	2				$	103				$	(6	)			$	(4	)
Fair Value Level 3 Rollforward
Recurring Basis
First Quarter 2014
	Fixed-Maturity Securities
	Obligations					Corporate Securities					RMBS					Asset-Backed Securities					Other					FG VIEs’					Other					Credit					FG VIEs' Liabilities					FG VIEs’ Liabilities
	of State and																				Invested					Assets at					Assets					Derivative					with					without
	Political																				Assets					Fair										Asset					Recourse,					Recourse,
	Subdivisions																									Value										(Liability),					at Fair					at Fair
																																				net(5)					Value					Value
	(in millions)
Fair value as of December 31, 2013	$	36				$	136				$	290				268					$	2				$	2,565				$	46				$	(1,693	)			$	(1,790	)			$	(1,081	)
Total pretax realized and unrealized gains/(losses) recorded in:(1)
Net income (loss)	1			(2	)	3			(2	)	4			(2	)	7			(2	)	—					82			(3	)	(9		)	(4	)	(211		)	(6	)	(72		)	(3	)	(9		)	(3	)
Other comprehensive income (loss)	1					4					14					8					1					—					—					—					—					—
Purchases	—					—					53					—					45			(7	)	—					—					—					—					—
Settlements	—					(5		)			(15		)			(31		)			—					(286		)			—					(19		)			269					12
FG VIE consolidations	—					—					—					—					—					—					—					—					—					—
FG VIE deconsolidations	—					—					13					—					—					(1,104		)			—					—					247					977
Fair value as of March 31, 2014	$	38				$	138				$	359				$	252				$	48				$	1,257				$	37				$	(1,923	)			$	(1,346	)			$	(101	)
Change in unrealized gains/(losses) related to financial instruments held as of March 31, 2014	$	1				$	4				$	15				$	7				$	1				$	25				$	(9	)			$	(232	)			$	(28	)			$	(10	)
______________
-1	Realized and unrealized gains (losses) from changes in values of Level 3 financial instruments represent gains (losses) from changes in values of those financial instruments only for the periods in which the instruments were classified as Level 3.
-2	Included in net realized investment gains (losses) and net investment income.
-3	Included in fair value gains (losses) on FG VIEs.
-4	Recorded in fair value gains (losses) on CCS.
-5	Represents net position of credit derivatives. The consolidated balance sheet presents gross assets and liabilities based on net counterparty exposure.
-6	Reported in net change in fair value of credit derivatives.
-7	Includes a non-cash transaction.
Level 3 Fair Value Disclosures
Quantitative Information About Level 3 Fair Value Inputs
At March 31, 2015
Financial Instrument Description (1)		Fair Value at				Significant Unobservable Inputs		Range						Weighted Average as a Percentage of Current Par Outstanding
		March 31, 2015
		(in millions)
Assets:
Fixed-maturity securities:
Obligations of state and political subdivisions		$	8			Rate of inflation		1		%	-	3.00%		2.00%
						Cash flow receipts		0.5		%	-	20.90%		12.90%
						Yield		4.60%
						Collateral recovery period		4 months			-	8.3 years		4.3 years
Corporate securities		79				Yield		18.00%
RMBS		383				CPR		0.3		%	-	7.50%		3.40%
						CDR		2.4		%	-	11.60%		5.50%
						Loss severity		50		%	-	100.00%		72.40%
						Yield		4.2		%	-	10.00%		5.90%
Asset-backed securities:
Investor owned utility		96				Cash flow receipts		100.00%
						Collateral recovery period		3.8 years
						Discount factor		7.00%
Triple-X life insurance transactions		130				Yield		6.80%
Other invested assets		81				Discount for lack of liquidity		20.00%
						Recovery on delinquent loans		40.00%
						Default rates		0		%	-	7.00%		6.10%
						Loss severity		40		%	-	75.00%		68.70%
						Prepayment speeds		6		%	-	15.00%		12.00%
						Net asset value (per share)		$	966		-	$1,147		$1,046
FG VIEs’ assets, at fair value		1,495				CPR		0.3		%	-	11.00%		2.60%
						CDR		1.7		%	-	13.10%		4.20%
						Loss severity		36		%	-	100.00%		64.20%
						Yield		2.7		%	-	16.70%		6.40%
Financial Instrument Description (1)		Fair Value at			Significant Unobservable Inputs		Range						Weighted Average as a Percentage of Current Par Outstanding
		March 31, 2015
		(in millions)
Other assets		37			Quotes from third party pricing		$	51		-	$60		$56
					Term (years)		5 years
Liabilities:
Credit derivative liabilities, net		(782	)		Year 1 loss estimates		0		%	-	50.00%		1.70%
					Hedge cost (in bps)		15			-	255.8		57.4
					Bank profit (in bps)		1			-	990		124.8
					Internal floor (in bps)		7			-	100		16.3
					Internal credit rating		AAA			-	CCC		AA
FG VIEs’ liabilities, at fair value		(1,423	)		CPR		0.3		%	-	11.00%		2.60%
					CDR		1.7		%	-	13.10%		4.20%
					Loss severity		36		%	-	100.00%		64.20%
					Yield		2.7		%	-	16.70%		5.50%
___________________
-1	Discounted cash flow is used as valuation technique for all financial instruments.
Quantitative Information About Level 3 Fair Value Inputs
At December 31, 2014
Financial Instrument Description (1)		Fair Value at				Significant Unobservable Inputs		Range						Weighted Average as a Percentage of Current Par Outstanding
		December 31, 2014
		(in millions)
Assets:
Fixed-maturity securities:
Obligations of state and political subdivisions		$	38			Rate of inflation		1		%	-	3.00%		2.00%
						Cash flow receipts		0.5		%	-	74.30%		63.00%
						Discount rates		4.6		%	-	8.00%		7.30%
						Collateral recovery period		1 month			-	34 years		28 years
Corporate securities		79				Yield		17.80%
RMBS		425				CPR		0.3		%	-	8.10%		3.30%
						CDR		2.7		%	-	10.60%		5.30%
						Loss severity		52.6		%	-	100.00%		75.20%
						Yield		4.7		%	-	11.70%		6.40%
Asset-backed securities:
Investor owned utility		95				Cash flow receipts		100%
						Collateral recovery period		4 years
						Discount factor		7.00%
Triple-X life insurance transactions		133				Yield		7.30%
Other invested assets		83				Discount for lack of liquidity		20.00%
						Recovery on delinquent loans		40.00%
						Default rates		0		%	-	7.00%		5.80%
						Loss severity		40		%	-	75.00%		68.30%
						Prepayment speeds		5		%	-	15.00%		12.30%
						Net asset value (per share)		$	965		-	$1,159		$1,082
FG VIEs’ assets, at fair value		1,398				CPR		0.3		%	-	11.00%		3.30%
						CDR		1.6		%	-	11.80%		5.10%
						Loss severity		40		%	-	100.00%		82.20%
						Yield		2.7		%	-	17.70%		7.90%
Financial Instrument Description (1)		Fair Value at			Significant Unobservable Inputs		Range					Weighted Average as a Percentage of Current Par Outstanding
		December 31, 2014
		(in millions)
Other assets		35			Quotes from third party pricing		$52		-	$61		$57
					Term (years)		5 years
Liabilities:
Credit derivative liabilities, net		(895	)		Year 1 loss estimates		0	%	-	93.00%		2.10%
					Hedge cost (in bps)		20		-	243.8		61.5
					Bank profit (in bps)		1		-	994.4		127
					Internal floor (in bps)		7		-	100		15.9
					Internal credit rating		AAA		-	CCC		AA+
FG VIEs’ liabilities, at fair value		(1,419	)		CPR		0.3	%	-	11.00%		3.30%
					CDR		1.6	%	-	11.80%		5.10%
					Loss severity		40	%	-	100.00%		82.20%
					Yield		2.7	%	-	17.70%		5.80%
____________________
-1	Discounted cash flow is used as valuation technique for all financial instruments.
The carrying amount and estimated fair value of the Company’s financial instruments are presented in the following table.
Fair Value of Financial Instruments
	As of								As of
	31-Mar-15								31-Dec-14
	Carrying				Estimated				Carrying				Estimated
	Amount				Fair Value				Amount				Fair Value
	(in millions)
Assets:
Fixed-maturity securities	$	9,833			$	9,833			$	10,491			$	10,491
Short-term investments	349				349				767				767
Other invested assets	114				116				108				110
Credit derivative assets	77				77				68				68
FG VIEs’ assets, at fair value	1,495				1,495				1,398				1,398
Other assets	189				189				184				184
Liabilities:
Financial guaranty insurance contracts(1)	3,719				6,343				3,823				6,205
Long-term debt	1,304				1,609				1,303				1,603
Credit derivative liabilities	859				859				963				963
FG VIEs’ liabilities with recourse, at fair value	1,278				1,278				1,277				1,277
FG VIEs’ liabilities without recourse, at fair value	145				145				142				142
Other liabilities	72				72				27				27
____________________
-1	Carrying amount includes the assets and liabilities related to financial guaranty insurance contract premiums, losses, and salvage and subrogation and other recoverables net of reinsurance.

Financial_Guaranty_Contracts_A

Financial Guaranty Contracts Accounted for as Credit Derivatives	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial Guaranty Contracts Accounted for as Credit Derivatives	Financial Guaranty Contracts Accounted for as Credit Derivatives
	Credit Derivatives
	The Company has a portfolio of financial guaranty contracts that meet the definition of a derivative in accordance with GAAP (primarily CDS).
	Credit derivative transactions are governed by ISDA documentation and have different characteristics from financial guaranty insurance contracts. For example, the Company’s control rights with respect to a reference obligation under a credit derivative may be more limited than when the Company issues a financial guaranty insurance contract. In addition, there are more circumstances under which the Company may be obligated to make payments. Similar to a financial guaranty insurance contract, the Company would be obligated to pay if the obligor failed to make a scheduled payment of principal or interest in full. However, the Company may also be required to pay if the obligor becomes bankrupt or if the reference obligation were restructured if, after negotiation, those credit events are specified in the documentation for the credit derivative transactions. Furthermore, the Company may be required to make a payment due to an event that is unrelated to the performance of the obligation referenced in the credit derivative. If events of default or termination events specified in the credit derivative documentation were to occur, the non-defaulting or the non-affected party, which may be either the Company or the counterparty, depending upon the circumstances, may decide to terminate a credit derivative prior to maturity. In that case, the Company may be required to make a termination payment to its swap counterparty upon such termination. The Company may not unilaterally terminate a CDS contract; however, the Company on occasion has mutually agreed with various counterparties to terminate certain CDS transactions.
	Credit Derivative Net Par Outstanding by Sector
	The estimated remaining weighted average life of credit derivatives was 4.7 years at March 31, 2015 and 4.7 years at December 31, 2014. The components of the Company’s credit derivative net par outstanding are presented below.
	Credit Derivatives
	Subordination and Ratings
			As of March 31, 2015												As of December 31, 2014
	Asset Type		Net Par				Original			Current			Weighted		Net Par			Original		Current		Weighted
			Outstanding				Subordination(1)			Subordination(1)			Average		Outstanding			Subordination(1)		Subordination(1)		Average
													Credit									Credit
													Rating									Rating
			(dollars in millions)
	Pooled corporate obligations:
	Collateralized loan obligation/collateral bond obligations		$	10,372			32	%		37.7	%		AAA		$	11,688		32	%	36.9	%	AAA
	Synthetic investment grade pooled corporate		6,363				22.3			20.2			AAA		7,640			22.6		20.6		AAA
	TruPS CDOs		2,948				45.6			37.5			BBB-		3,119			45.3		35.8		BBB-
	Market value CDOs of corporate obligations		1,052				17			15.7			AAA		1,174			19.1		20.7		AAA
	Total pooled corporate obligations		20,735				30.2			31.2			AAA		23,621			30.1		30.7		AAA
	U.S. RMBS:
	Option ARM and Alt-A first lien		1,321				16.2			10.5			BB+		1,378			16.3		10.7		BB+
	Subprime first lien		1,315				31.3			49.9			A		1,366			31.1		50.5		A
	Prime first lien		213				10.9			0			B		223			10.9		0		B
	Closed-end second lien		19				—			—			CCC		19			—		—		CCC
	Total U.S. RMBS		2,868				24.8			33.3			BBB		2,986			24.8		33.9		BBB
	CMBS		1,785				35.9			45.5			AAA		1,952			35.3		43.6		AAA
	Other		6,343				—			—			A		6,437			—		—		A
	Total		$	31,731									AA		$	34,996						AA+
	____________________
	-1	Represents the sum of subordinate tranches and over-collateralization and does not include any benefit from excess interest collections that may be used to absorb losses.
	Except for TruPS CDOs, the Company’s exposure to pooled corporate obligations is highly diversified in terms of obligors and industries. Most pooled corporate transactions are structured to limit exposure to any given obligor and industry. The majority of the Company’s pooled corporate exposure consists of collateralized loan obligation (“CLO”) or synthetic pooled corporate obligations. Most of these CLOs have an average obligor size of less than 1% of the total transaction and typically restrict the maximum exposure to any one industry to approximately 10%. The Company’s exposure also benefits from embedded credit enhancement in the transactions which allows a transaction to sustain a certain level of losses in the underlying collateral, further insulating the Company from industry specific concentrations of credit risk on these deals.
	The Company’s TruPS CDO asset pools are generally less diversified by obligors and industries than the typical CLO asset pool. Also, the underlying collateral in TruPS CDOs consists primarily of subordinated debt instruments such as TruPS issued by bank holding companies and similar instruments issued by insurance companies, REITs and other real estate related issuers while CLOs typically contain primarily senior secured obligations. However, to mitigate these risks TruPS CDOs were typically structured with higher levels of embedded credit enhancement than typical CLOs.
	The Company’s exposure to “Other” CDS contracts is also highly diversified. It includes $1.9 billion of exposure to one pooled infrastructure transaction comprising diversified pools of international infrastructure project transactions and loans to regulated utilities. These pools were all structured with underlying credit enhancement sufficient for the Company to attach at AAA levels at origination. The remaining $4.4 billion of exposure in “Other” CDS contracts comprises numerous deals across various asset classes, such as commercial receivables, international RMBS, infrastructure, regulated utilities and consumer receivables.
	Distribution of Credit Derivative Net Par Outstanding by Internal Rating
			As of March 31, 2015							As of December 31, 2014
	Ratings		Net Par				% of Total			Net Par				% of Total
			Outstanding							Outstanding
			(dollars in millions)
	AAA		$	19,132			60.3	%		$	21,817			62.3	%
	AA		5,195				16.4			5,398				15.4
	A		1,865				5.9			1,982				5.7
	BBB		2,616				8.2			2,774				8
	BIG		2,923				9.2			3,025				8.6
	Credit derivative net par outstanding		$	31,731			100	%		$	34,996			100	%
	Fair Value of Credit Derivatives
	Net Change in Fair Value of Credit Derivatives Gain (Loss)
		First Quarter
		2015				2014
		(in millions)
	Realized gains on credit derivatives (1)	$	23			$	20
	Net credit derivative losses (paid and payable) recovered and recoverable and other settlements	(2		)		(1		)
	Realized gains (losses) and other settlements on credit derivatives	21				19
	Net change in unrealized gains (losses) on credit derivatives:
	Pooled corporate obligations	17				(58		)
	U.S. RMBS	75				(140		)
	CMBS	0				0
	Other	11				(32		)
	Net change in unrealized gains (losses) on credit derivatives	103				(230		)
	Net change in fair value of credit derivatives	$	124			$	(211	)
	____________________
	-1	Includes realized gain due to terminations of CDS contracts of $11 million and $0.2 million for First Quarter 2015 and First Quarter 2014, respectively. Net par of $93 million and $1.1 billion were terminated in First Quarter 2015 and First Quarter 2014, respectively. CDS terminations reflect a payment received from the resolution of a dispute related to a termination of CDS in 2008.
	During First Quarter 2015, unrealized fair value gains were generated primarily in the U.S. RMBS prime first lien and Option ARM sectors. The change in fair value of credit derivatives in First Quarter 2015 was primarily due to a refinement in methodology to address an instance in a U.S. RMBS transaction where the Company now expects recoveries.  This refinement resulted in approximately $49 million in fair value gains in First Quarter 2015. In addition, there were unrealized gains in the TruPS CDO and Other sectors as result of price improvements on the underlying collateral. The changes in the Company’s CDS spreads did not have a material impact during the quarter.
	During First Quarter 2014, unrealized fair value losses were generated primarily in the U.S. RMBS prime first lien, Alt-A, Option ARM and subprime sectors, as well as pooled corporate obligations, due to wider implied net spreads. The wider implied net spreads were primarily a result of the decreased cost to buy protection in AGC’s name as the market cost of AGC’s credit protection decreased significantly during the period. These transactions were pricing at or above their floor levels; therefore when the cost of purchasing CDS protection on AGC, which management refers to as the CDS spread on AGC, decreased, the implied spreads that the Company would expect to receive on these transactions increased. The cost of AGM’s credit protection also decreased during First Quarter 2014 generating unrealized fair value losses on a Triple-X life insurance securitization transaction, due to wider implied net spreads. This did not have a significant impact on the remainder of AGM’s portfolio, as a significant portion of AGM’s policies continue to price at floor levels.
The impact of changes in credit spreads will vary based upon the volume, tenor, interest rates, and other market conditions at the time these fair values are determined. In addition, since each transaction has unique collateral and structural terms, the underlying change in fair value of each transaction may vary considerably. The fair value of credit derivative contracts also reflects the change in the Company’s own credit cost based on the price to purchase credit protection on AGC and AGM. The Company determines its own credit risk based on quoted CDS prices traded on the Company at each balance sheet date.
Five-Year CDS Spread
on AGC and AGM
Quoted price of CDS contract (in basis points)
	As of			As of			As of			As of
	31-Mar-15			31-Dec-14			31-Mar-14			31-Dec-13
AGC	317			323			291			460
AGM	341			325			305			525
One-Year CDS Spread
on AGC and AGM
Quoted price of CDS contract (in basis points)
	As of			As of			As of			As of
	31-Mar-15			31-Dec-14			31-Mar-14			31-Dec-13
AGC	60			80			55			185
AGM	80			85			70			220
Fair Value of Credit Derivatives Assets (Liabilities)
and Effect of AGC and AGM
Credit Spreads
	As of				As of
	31-Mar-15				31-Dec-14
	(in millions)
Fair value of credit derivatives before effect of AGC and AGM credit spreads	$	(1,820	)		$	(2,029	)
Plus: Effect of AGC and AGM credit spreads	1,038				1,134
Net fair value of credit derivatives	$	(782	)		$	(895	)
The fair value of CDS contracts at March 31, 2015, before considering the implications of AGC’s and AGM’s credit spreads, is a direct result of continued wide credit spreads in the fixed income security markets and ratings downgrades. The asset classes that remain most affected are 2005-2007 vintages of prime first lien, Alt-A, Option ARM, subprime RMBS deals as well as TruPS and pooled corporate securities. Comparing March 31, 2015 with December 31, 2014, there was a narrowing of spreads primarily related to Alt-A first lien, Option ARM, and subprime RMBS transactions, as well as the Company's pooled corporate obligations. This narrowing of spreads combined with the runoff of par outstanding and termination of CDS contracts, resulted in a gain of approximately $209 million, before taking into account AGC’s or AGM’s credit spreads.
Management believes that the trading level of AGC’s and AGM’s credit spreads over the past several years has been due to the correlation between AGC’s and AGM’s risk profile and the current risk profile of the broader financial markets and to increased demand for credit protection against AGC and AGM as the result of its financial guaranty volume, as well as the overall lack of liquidity in the CDS market. Offsetting the benefit attributable to AGC’s and AGM’s credit spread were higher credit spreads in the fixed income security markets. The higher credit spreads in the fixed income security market are due to the lack of liquidity in the high yield CDO, TruPS CDO, and CLO markets as well as continuing market concerns over the 2005-2007 vintages of RMBS.
The following table presents the fair value and the present value of expected claim payments or recoveries (i.e. net expected loss to be paid as described in Note 5) for contracts accounted for as derivatives.
Net Fair Value and Expected Losses
of Credit Derivatives by Sector
		Fair Value of Credit Derivative								Expected Loss to be (Paid) Recovered (1)
		Asset (Liability), net
Asset Type		As of				As of				As of				As of
		31-Mar-15				31-Dec-14				31-Mar-15				31-Dec-14
		(in millions)
Pooled corporate obligations		$	(22	)		$	(49	)		$	(13	)		$	(23	)
U.S. RMBS		(419		)		(494		)		(66		)		(73		)
CMBS		0				0				—				—
Other		(341		)		(352		)		37				38
Total		$	(782	)		$	(895	)		$	(42	)		$	(58	)
____________________
(1)	Includes R&W benefit of $75 million as of March 31, 2015 and $86 million as of December 31, 2014.
Ratings Sensitivities of Credit Derivative Contracts
Within the Company's insured CDS portfolio, the transaction documentation for approximately $5.7 billion in CDS gross par insured as of March 31, 2015 requires AGC and AGRO to post eligible collateral to secure its obligations to make payments under such contracts. Eligible collateral is generally cash or U.S. government or agency securities; eligible collateral other than cash is valued at a discount to the face amount.
•	For approximately $5.5 billion of such contracts, AGC has negotiated caps such that the posting requirement cannot exceed a certain fixed amount, regardless of the mark-to-market valuation of the exposure or the financial strength ratings of AGC. For such contracts, AGC need not post on a cash basis more than $665 million, although the value of the collateral posted may exceed such fixed amount depending on the advance rate agreed with the counterparty for the particular type of collateral posted.
•	For the remaining approximately $241 million of such contracts, AGC or AGRO could be required from time to time to post additional collateral without such cap based on movements in the mark-to-market valuation of the underlying exposure.
As of March 31, 2015, the Company posted approximately $356 million to secure obligations under its CDS exposure, of which approximately $21 million related to such $241 million of notional. As of December 31, 2014, the Company posted approximately $376 million, of which approximately $25 million related to $242 million of notional where AGC or AGRO could be required to post additional collateral based on movements in the mark-to-market valuation of the underlying exposure.
Sensitivity to Changes in Credit Spread
The following table summarizes the estimated change in fair values on the net balance of the Company’s credit derivative positions assuming immediate parallel shifts in credit spreads on AGC and AGM and on the risks that they both assume.
Effect of Changes in Credit Spread
As of March 31, 2015
Credit Spreads(1)		Estimated Net				Estimated Change
		Fair Value				in Gain/(Loss)
		(Pre-Tax)				(Pre-Tax)
		(in millions)
100% widening in spreads		$	(1,590	)		$	(808	)
50% widening in spreads		(1,186		)		(404		)
25% widening in spreads		(986		)		(204		)
10% widening in spreads		(864		)		(82		)
Base Scenario		(782		)		—
10% narrowing in spreads		(706		)		76
25% narrowing in spreads		(593		)		189
50% narrowing in spreads		(407		)		375
____________________
-1	Includes the effects of spreads on both the underlying asset classes and the Company’s own credit spread.

Consolidated_Variable_Interest

Consolidated Variable Interest Entities	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidated Variable Interest Entities	Consolidated Variable Interest Entities
	The Company provides financial guaranties with respect to debt obligations of special purpose entities, including VIEs. Assured Guaranty does not act as the servicer or collateral manager for any VIE obligations insured by its companies. The transaction structure generally provides certain financial protections to the Company. This financial protection can take several forms, the most common of which are overcollateralization, first loss protection (or subordination) and excess spread. In the case of overcollateralization (i.e., the principal amount of the securitized assets exceeds the principal amount of the structured finance obligations guaranteed by the Company), the structure allows defaults of the securitized assets before a default is experienced on the structured finance obligation guaranteed by the Company. In the case of first loss, the financial guaranty insurance policy only covers a senior layer of losses experienced by multiple obligations issued by special purpose entities, including VIEs. The first loss exposure with respect to the assets is either retained by the seller or sold off in the form of equity or mezzanine debt to other investors. In the case of excess spread, the financial assets contributed to special purpose entities, including VIEs, generate cash flows that are in excess of the interest payments on the debt issued by the special purpose entity. Such excess spread is typically distributed through the transaction’s cash flow waterfall and may be used to create additional credit enhancement, applied to redeem debt issued by the special purpose entities, including VIEs (thereby, creating additional overcollateralization), or distributed to equity or other investors in the transaction.
	Assured Guaranty is not primarily liable for the debt obligations issued by the VIEs it insures and would only be required to make payments on those insured debt obligations in the event that the issuer of such debt obligations defaults on any principal or interest due and only for the amount of the shortfall. AGL’s and its Subsidiaries’ creditors do not have any rights with regard to the collateral supporting the debt issued by the FG VIEs. Proceeds from sales, maturities, prepayments and interest from such underlying collateral may only be used to pay Debt Service on VIE liabilities. Net fair value gains and losses on FG VIEs are expected to reverse to zero at maturity of the VIE debt, except for net premiums received and net claims paid by Assured Guaranty under the financial guaranty insurance contract. The Company’s estimate of expected loss to be paid for FG VIEs is included in Note 5, Expected Loss to be Paid.
	As part of the terms of its financial guaranty contracts, the Company obtains certain protective rights with respect to the VIE that are triggered by the occurrence of certain events, such as failure to be in compliance with a covenant due to poor deal performance or a deterioration in a servicer or collateral manager's financial condition. At deal inception, the Company typically is not deemed to control a VIE; however, once a trigger event occurs, the Company's control of the VIE typically increases. The Company continuously evaluates its power to direct the activities that most significantly impact the economic performance of VIEs that have debt obligations insured by the Company and, accordingly, where the Company is obligated to absorb VIE losses or receive benefits that could potentially be significant to the VIE. The Company obtains protective rights under its insurance contracts that give the Company additional controls over a VIE if there is either deterioration of deal performance or in the financial health of the deal servicer. The Company is deemed to be the control party for certain VIEs under GAAP, typically when its protective rights give it the power to both terminate and replace the deal servicer, which are characteristics specific to the Company's financial guaranty contracts. If the protective rights that could make the Company the control party have not been triggered, then the VIE is not consolidated. If the Company is deemed no longer to have those protective rights, the transaction is deconsolidated.
	Consolidated FG VIEs
	Number of FG VIEs Consolidated
		First Quarter
		2015			2014
	Beginning of the period, December 31	32			40
	Consolidated (1)	1			—
	Deconsolidated (1)	—			(7	)
	Matured	—			(2	)
	End of the period, March 31	33			31
	____________________
	-1	Net loss on consolidation was $26 million in First Quarter 2015, and net gain on deconsolidation was $120 million in First Quarter 2014, and recorded in “fair value gains (losses) on FG VIEs” in the consolidated statement of operations.
	The total unpaid principal balance for the FG VIEs’ assets that were over 90 days or more past due was approximately $218 million at March 31, 2015 and $183 million at December 31, 2014. The aggregate unpaid principal of the FG VIEs’ assets was approximately $942 million greater than the aggregate fair value at March 31, 2015, excluding the effect of R&W settlements. The aggregate unpaid principal of the FG VIEs’ assets was approximately $941 million greater than the aggregate fair value at December 31, 2014, excluding the effect of R&W settlements. The change in the instrument-specific credit risk of the FG VIEs’ assets held as of March 31, 2015 that was recorded in the consolidated statements of operations for First Quarter 2015 were gains of $18 million. The change in the instrument-specific credit risk of the FG VIEs’ assets held as of March 31, 2014 that was recorded in the consolidated statements of operations for First Quarter 2014 were gains of $58 million. To calculate the instrument specific credit risk, the changes in the fair value of the FG VIE assets are allocated between those changes that are due to the instrument specific credit risk and those are due to other factors, including interest rates. The instrument specific credit risk amount is determined by using expected contractual cash flows versus current expected cash flows discounted at original contractual rate. The net present value is calculated by discounting the expected cash flows of the underlying security, excluding the Company’s financial guaranty insurance, at the relevant effective interest rate.
	The unpaid principal for FG VIE liabilities with recourse was $2,017 million and $1,912 million as of March 31, 2015 and December 31, 2014, respectively. FG VIE liabilities with recourse will mature at various dates ranging from 2025 to 2046. The aggregate unpaid principal balance of the FG VIE liabilities with and without recourse was approximately $1,014 million greater than the aggregate fair value of the FG VIEs’ liabilities as of March 31, 2015. The aggregate unpaid principal balance was approximately $916 million greater than the aggregate fair value of the FG VIEs' liabilities as of December 31, 2014.
	The table below shows the carrying value of the consolidated FG VIEs’ assets and liabilities in the consolidated financial statements, segregated by the types of assets that collateralize their respective debt obligations for FG VIE liabilities with recourse.
	Consolidated FG VIEs
	By Type of Collateral
		As of March 31, 2015							As of December 31, 2014
		Assets				Liabilities			Assets		Liabilities
		(in millions)
	With recourse:
	U.S. RMBS first lien	$	739			$	591		$	632	$	581
	U.S. RMBS second lien	228				322			238		327
	Other	365				365			369		369
	Total with recourse	1,332				1,278			1,239		1,277
	Without recourse	167				145			163		142
	Total	$	1,499			$	1,423		$	1,402	$	1,419
	The consolidation of FG VIEs has a significant effect on net income and shareholder’s equity due to (1) changes in fair value gains (losses) on FG VIE assets and liabilities, (2) the elimination of premiums and losses related to the AGC and AGM FG VIE liabilities with recourse and (3) the elimination of investment balances related to the Company’s purchase of AGC and AGM insured FG VIE debt. Upon consolidation of a FG VIE, the related insurance and, if applicable, the related investment balances, are considered intercompany transactions and therefore eliminated. Such eliminations are included in the table below to present the full effect of consolidating FG VIEs.
	Effect of Consolidating FG VIEs on Net Income,
	Cash Flows From Operating Activities and Shareholders’ Equity
		First Quarter
		2015				2014
	Net earned premiums	$	(5	)		$	(17	)
	Net investment income	(3		)		(3		)
	Fair value gains (losses) on FG VIEs	(7		)		157
	Other income (loss)	0				(2		)
	Loss and LAE	5				(1		)
	Effect on net income before tax	(10		)		134
	Less: tax provision (benefit)	(4		)		47
	Effect on net income (loss)	$	(6	)		$	87
	Effect on cash flows from operating activities	$	18			$	(8	)
		As of				As of
		31-Mar-15				31-Dec-14
		(in millions)
	Effect on shareholders’ equity (decrease) increase	$	(49	)		$	(44	)
	Fair value gains (losses) on FG VIEs represent the net change in fair value on the consolidated FG VIEs’ assets and liabilities. During First Quarter 2015, the Company recorded a pre-tax net fair value loss on consolidated FG VIEs of $7 million. The primary driver of the loss was a pre-tax net fair value loss of $26 million on the consolidation of one new FG VIE. The net fair value loss on consolidation was partially offset by net mark-to-market gains due to price application on the FG VIE assets during the quarter resulting from improvements in the underlying collateral.
	During First Quarter 2014, the Company recorded a pre-tax net fair value gain of consolidated FG VIEs of $157 million. The primary driver of this gain, $120 million, was a result of the deconsolidation of seven VIEs. There was an additional gain of $37 million resulting from the Company exercising its option to accelerate two second lien RMBS VIEs. These two VIEs were treated as maturities during the period.
	Non-Consolidated VIEs
	As of March 31, 2015 and December 31, 2014, the Company had issued financial guaranty contracts for approximately 900 and 930 VIEs, respectively, that it did not consolidate. To date, the Company’s analyses have indicated that it does not have a controlling financial interest in any other VIEs and, as a result, they are not consolidated in the consolidated financial statements. The Company’s exposure provided through its financial guaranties with respect to debt obligations of special purpose entities is included within net par outstanding in Note 3, Outstanding Exposure.

Investments_and_Cash

Investments and Cash	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Investments and Cash	Investments and Cash
	Net Investment Income and Realized Gains (Losses)
	Net investment income is a function of the yield that the Company earns on invested assets and the size of the portfolio. The investment yield is a function of market interest rates at the time of investment as well as the type, credit quality and maturity of the invested assets. Accrued investment income was $93 million and $98 million as of March 31, 2015 and December 31, 2014, respectively.
	Net Investment Income
		First Quarter
		2015			2014
		(in millions)
	Income from fixed-maturity securities managed by third parties	$	82		$	80
	Income from internally managed securities:
	Fixed maturities	15			20
	Other invested assets	6			5
	Gross investment income	103			105
	Investment expenses	(2		)	(2		)
	Net investment income	$	101		$	103
	Net Realized Investment Gains (Losses)
		First Quarter
		2015			2014
		(in millions)
	Gross realized gains on available-for-sale securities	$	24		$	4
	Gross realized gains on other assets in investment portfolio	1			5
	Gross realized losses on available-for-sale securities	(1		)	(2		)
	Gross realized losses on other assets in investment portfolio	(1		)	0
	Other-than-temporary impairment	(7		)	(5		)
	Net realized investment gains (losses)	$	16		$	2
	The following table presents the roll-forward of the credit losses of fixed-maturity securities for which the Company has recognized an other-than-temporary-impairment and where the portion of the fair value adjustment related to other factors was recognized in other comprehensive income ("OCI").
	Roll Forward of Credit Losses
	in the Investment Portfolio
		First Quarter
		2015			2014
		(in millions)
	Balance, beginning of period	$	124		$	80
	Additions for credit losses on securities for which an other-than-temporary-impairment was not previously recognized	—			1
	Reductions for securities sold and other settlement during the period	(21		)	—
	Additions for credit losses on securities for which an other-than-temporary-impairment was previously recognized	3			4
	Balance, end of period	$	106		$	85
	Investment Portfolio
	Fixed-Maturity Securities and Short-Term Investments
	by Security Type
	As of March 31, 2015
	Investment Category		Percent		Amortized			Gross		Gross			Estimated		AOCI(2)			Weighted
			of		Cost			Unrealized		Unrealized			Fair		Gain			Average
			Total(1)					Gains		Losses			Value		(Loss) on			Credit
															Securities			Rating
															with			(3)
															Other-Than-Temporary Impairment
			(dollars in millions)
	Fixed-maturity securities:
	Obligations of state and political subdivisions		52	%	$	5,099		$	361	$	(2	)	$	5,458	$	4		AA
	U.S. government and agencies		5		464			33		0			497		—			AA+
	Corporate securities		14		1,340			65		(6		)	1,399		(4		)	A
	Mortgage-backed securities(4):		0
	RMBS		12		1,145			56		(16		)	1,185		5			A
	CMBS		6		573			27		0			600		—			AAA
	Asset-backed securities		4		394			7		—			401		3			BBB-
	Foreign government securities		3		295			6		(8		)	293		0			AA+
	Total fixed-maturity securities		96		9,310			555		(32		)	9,833		8			AA-
	Short-term investments		4		349			0		0			349		—			AAA
	Total investment portfolio		100	%	$	9,659		$	555	$	(32	)	$	10,182	$	8		AA-
	Fixed-Maturity Securities and Short-Term Investments
	by Security Type
	As of December 31, 2014
	Investment Category		Percent		Amortized			Gross		Gross			Estimated		AOCI			Weighted
			of		Cost			Unrealized		Unrealized			Fair		Gain			Average
			Total(1)					Gains		Losses			Value		(Loss) on			Credit
													Securities			Rating
													with			(3)
													Other-Than-Temporary Impairment
		(dollars in millions)
Fixed-maturity securities:
Obligations of state and political subdivisions		50	%	$	5,416		$	380	$	(1	)	$	5,795	$	7		AA
U.S. government and agencies		6		635			31		(1		)	665		—			AA+
Corporate securities		12		1,320			53		(5		)	1,368		(2		)	A
Mortgage-backed securities(4):
RMBS		12		1,255			51		(21		)	1,285		0			A-
CMBS		6		639			20		0			659		—			AAA
Asset-backed securities		4		411			9		(3		)	417		3			BBB-
Foreign government securities		3		296			8		(2		)	302		—			AA+
Total fixed-maturity securities		93		9,972			552		(33		)	10,491		8			AA-
Short-term investments		7		767			0		0			767		0			AA+
Total investment portfolio		100	%	$	10,739		$	552	$	(33	)	$	11,258	$	8		AA-
____________________
-1	Based on amortized cost.
-2	Accumulated OCI. See also Note 17, Shareholders' Equity.
-3	Ratings in the tables above represent the lower of the Moody’s and S&P classifications except for bonds purchased for loss mitigation or risk management strategies, which use internal ratings classifications. The Company’s portfolio consists primarily of high-quality, liquid instruments.
-4	Government-agency obligations were approximately 47% of mortgage backed securities as of March 31, 2015 and 44% as of December 31, 2014 based on fair value.
The Company’s investment portfolio in tax-exempt and taxable municipal securities includes issuances by a wide number of municipal authorities across the U.S. and its territories. Securities rated lower than A-/A3 by S&P or Moody’s are not eligible to be purchased for the Company’s portfolio unless acquired for loss mitigation or risk management strategies.
The majority of the investment portfolio is managed by four outside managers. The Company has established detailed guidelines regarding credit quality, exposure to a particular sector and exposure to a particular obligor within a sector.
The following tables summarize, for all securities in an unrealized loss position, the aggregate fair value and gross unrealized loss by length of time the amounts have continuously been in an unrealized loss position.
Fixed-Maturity Securities
Gross Unrealized Loss by Length of Time
As of March 31, 2015
	Less than 12 months						12 months or more					Total
	Fair			Unrealized			Fair		Unrealized			Fair		Unrealized
	Value			Loss			Value		Loss			Value		Loss
	(dollars in millions)
Obligations of state and political subdivisions	$	189		$	(2	)	$	5	$	0		$	194	$	(2	)
U.S. government and agencies	26			0			12		0			38		0
Corporate securities	194			(6		)	5		0			199		(6		)
Mortgage-backed securities:
RMBS	94			(1		)	85		(15		)	179		(16		)
CMBS	21			0			2		0			23		0
Asset-backed securities	—			—			—		—			—		—
Foreign government securities	156			(8		)	—		—			156		(8		)
Total	$	680		$	(17	)	$	109	$	(15	)	$	789	$	(32	)
Number of securities (1)				166					24					187
Number of securities with other-than-temporary impairment				2					3					5
Fixed-Maturity Securities
Gross Unrealized Loss by Length of Time
As of December 31, 2014
	Less than 12 months						12 months or more					Total
	Fair			Unrealized			Fair		Unrealized			Fair		Unrealized
	Value			Loss			Value		Loss			Value		Loss
	(dollars in millions)
Obligations of state and political subdivisions	$	64		$	0		$	25	$	(1	)	$	89	$	(1	)
U.S. government and agencies	139			0			68		(1		)	207		(1		)
Corporate securities	189			(3		)	104		(2		)	293		(5		)
Mortgage-backed securities:
RMBS	205			(3		)	159		(18		)	364		(21		)
CMBS	36			0			19		0			55		0
Asset-backed securities	56			(2		)	18		(1		)	74		(3		)
Foreign government securities	108			(2		)	0		0			108		(2		)
Total	$	797		$	(10	)	$	393	$	(23	)	$	1,190	$	(33	)
Number of securities (1)				125					82					198
Number of securities with other-than-temporary impairment				3					7					10
___________________
-1	The number of securities does not add across because lots of the same securities have been purchased at different times and appear in both categories above (i.e. Less than 12 months and 12 months or more). If a security appears in both categories, it is counted only once in the total column.
Of the securities in an unrealized loss position for 12 months or more as of March 31, 2015, four securities had unrealized losses greater than 10% of book value. The total unrealized loss for these securities as of March 31, 2015 was $14 million. The Company has determined that the unrealized losses recorded as of March 31, 2015 are yield related and not the result of other-than-temporary-impairment.
The amortized cost and estimated fair value of available-for-sale fixed maturity securities by contractual maturity as of March 31, 2015 are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.
Distribution of Fixed-Maturity Securities
by Contractual Maturity
As of March 31, 2015
	Amortized			Estimated
	Cost			Fair Value
	(in millions)
Due within one year	$	156		$	158
Due after one year through five years	1,706			1,763
Due after five years through 10 years	2,146			2,288
Due after 10 years	3,584			3,839
Mortgage-backed securities:
RMBS	1,145			1,185
CMBS	573			600
Total	$	9,310		$	9,833
The investment portfolio and miscellaneous other assets/liabilities contain securities and cash that are either held in trust for the benefit of third party reinsurers in accordance with statutory requirements, placed on deposit to fulfill state licensing requirements, or otherwise restricted in the amount of $215 million and $236 million as of March 31, 2015 and December 31, 2014, respectively, based on fair value. The investment portfolio also contains securities that are held in trust by certain AGL subsidiaries for the benefit of other AGL subsidiaries in accordance with statutory and regulatory requirements in the amount of $1,420 million and $1,395 million as of March 31, 2015 and December 31, 2014, respectively, based on fair value.
The fair value of the Company’s pledged securities to secure its obligations under its CDS exposure totaled $356 million and $376 million as of March 31, 2015 and December 31, 2014, respectively.
No material investments of the Company were non-income producing for First Quarter 2015 and First Quarter 2014, respectively.
Internally Managed Portfolio
The investment portfolio tables shown above include both assets managed externally and internally. In the table below, more detailed information is provided for the component of the total investment portfolio that is internally managed (excluding short-term investments). The internally managed portfolio, as defined below, represents approximately 8% and 8% of the investment portfolio, on a fair value basis as of March 31, 2015 and December 31, 2014, respectively. The internally managed portfolio consists primarily of the Company's investments in securities for (i) loss mitigation purposes, (ii) other risk management purposes and (iii) where the Company believes a particular security presents an attractive investment opportunity.
One of the Company's strategies for mitigating losses has been to purchase securities it has insured that have expected losses, at discounted prices (assets purchased for loss mitigation purposes). In addition, the Company holds other invested assets that were obtained or purchased as part of negotiated settlements with insured counterparties or under the terms of our financial guaranties (other risk management assets).
Internally Managed Portfolio
Carrying Value
	As of			As of
	31-Mar-15			31-Dec-14
	(in millions)
Assets purchased for loss mitigation and other risk management purposes:
Fixed-maturity securities	721			835
Other invested assets	41			46
Other	91			79
Total	$	853		$	960

Insurance_Company_Regulatory_R

Insurance Company Regulatory Requirements	3 Months Ended
	Mar. 31, 2015
Insurance Company Regulatory Requirements [Abstract]
Insurance Company Regulatory Requirements	Insurance Company Regulatory Requirements
	Contingency Reserves
	On July 15, 2013, AGM and its wholly-owned subsidiary AGE (together, the "AGM Group") and AGC, were notified that the New York State Department of Financial Services ("NYDFS") and the Maryland Insurance Administration (“MIA”) do not object to the AGM Group and AGC, respectively, reassuming contingency reserves in the amount of approximately $250 million, in the case of the AGM Group, and $267 million, in the case of AGC, that they had ceded to AG Re and electing to cease ceding future contingency reserves to AG Re. The insurance regulators permitted the AGM Group and AGC to reassume the contingency reserves in increments over three years. As of March 31, 2015, the AGM Group and AGC had reassumed an aggregate of $428 million. One more installment remains to be reassumed in the third quarter of 2015, subject to the prior approval of the NYDFS, in the case of the AGM Group, and the MIA and the NYDFS, in the case of AGC.
	With respect to the regular, quarterly contributions to contingency reserves required by the applicable Maryland and New York laws and regulations, such laws and regulations permit the discontinuation of such quarterly contributions to a company’s contingency reserves when such company’s aggregate contingency reserves for a particular line of business (i.e., municipal or non-municipal) exceed the sum of the company’s outstanding principal for each specified category of obligations within the particular line of business multiplied by the specified contingency reserve factor for each such category.  In accordance with such laws and regulations, and with the approval of the MIA and the NYDFS, respectively, AGC ceased making quarterly contributions to its contingency reserves for both municipal and non-municipal business and AGM ceased making quarterly contributions to its contingency reserves for non-municipal business, in each case beginning in the fourth quarter of 2014. Such cessations are expected to continue for as long as AGC and AGM satisfy the foregoing condition for their applicable line(s) of business.
	Dividend Restrictions and Capital Requirements
	Under New York insurance law, AGM may only pay dividends out of "earned surplus", which is the portion of a company's surplus that represents the net earnings, gains or profits (after deduction of all losses) that have not been distributed to shareholders as dividends or transferred to stated capital or capital surplus, or applied to other purposes permitted by law, but does not include unrealized appreciation of assets. AGM may pay dividends without the prior approval of the New York Superintendent of Financial Services ("New York Superintendent") that, together with all dividends declared or distributed by it during the preceding 12 months, does not exceed the lesser of 10% of its policyholders' surplus (as of the last annual or quarterly statement filed with the New York Superintendent) or 100% of its adjusted net investment income during that period. The maximum amount available during 2015 for AGM to distribute as dividends without regulatory approval is estimated to be approximately $221 million, of which approximately $40 million is estimated to be available for distribution in the second quarter of 2015.
	Under Maryland's insurance law, AGC may, with prior notice to the Maryland Insurance Commissioner, pay an ordinary dividend that, together with all dividends paid in the prior 12 months, does not exceed 10% of its policyholders' surplus (as of the prior December 31) or 100% of its adjusted net investment income during that period. The maximum amount available during 2015 for AGC to distribute as ordinary dividends will be approximately $90 million, of which approximately $16 million is available for distribution in the second quarter of 2015.
	MAC is a New York domiciled insurance company subject to the same dividend limitations described above for AGM. The Company does not currently anticipate that MAC will distribute any dividends.
	Any distribution (including repurchase of shares) of any share capital, contributed surplus or other statutory capital) that would reduce AG Re's total statutory capital by 15% or more of its total statutory capital as set out in its previous year's financial statements requires the prior approval of the Bermuda Monetary Authority ("Authority"). Separately, dividends are paid out of an insurer's statutory surplus and cannot exceed that surplus. Further, annual dividends cannot exceed 25% of total statutory capital and surplus as set out in its previous year's financial statements, which is $279 million, without AG Re certifying to the Authority that it will continue to meet required margins. Based on the foregoing limitations, in 2015 AG Re has the capacity to (i) make capital distributions in an aggregate amount up to $127 million without the prior approval of the Authority and (ii) declare and pay dividends in an aggregate amount up to the limit of its outstanding statutory surplus, which is $271 million. Such dividend capacity is further limited by the actual amount of AG Re’s unencumbered assets, which amount changes from time to time due in part to collateral posting requirements. As of March 31, 2015, AG Re had unencumbered assets of approximately $588 million.
	U.K. company law prohibits each of AGE and AGUK from declaring a dividend to its shareholders unless it has “profits available for distribution.” The determination of whether a company has profits available for distribution is based on its accumulated realized profits less its accumulated realized losses. While the U.K. insurance regulatory laws impose no statutory restrictions on a general insurer's ability to declare a dividend, the Prudential Regulation Authority's capital requirements may in practice act as a restriction on dividends. The Company does not expect AGE or AGUK to distribute any dividends at this time.
	Dividends and Surplus Notes
	By Insurance Company Subsidiaries
		First Quarter
		2015		2014
		(in millions)
	Dividends paid by AGC to AGUS	$	20	$	—
	Dividends paid by AGM to AGMH	66		—
	Dividends paid by AG Re to AGL	50		62
	Repayment of surplus note by AGM to AGMH	25		25

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	Overview
	AGL, and its "Bermuda Subsidiaries," which consist of AG Re, AGRO, and Cedar Personnel Ltd., are not subject to any income, withholding or capital gains taxes under current Bermuda law. The Company has received an assurance from the Minister of Finance in Bermuda that, in the event of any taxes being imposed, AGL and its Bermuda Subsidiaries will be exempt from taxation in Bermuda until March 31, 2035. AGL's U.S. and U.K. subsidiaries are subject to income taxes imposed by U.S. and U.K. authorities, respectively, and file applicable tax returns. In addition, AGRO, a Bermuda domiciled company and AGE, a U.K. domiciled company, have elected under Section 953(d) of the U.S. Internal Revenue Code to be taxed as a U.S. domestic corporation.
	In November 2013, AGL became tax resident in the U.K. although it will remain a Bermuda-based company and its administrative and head office functions will continue to be carried on in Bermuda. As a company that is not incorporated in the U.K., AGL currently intends to manage the affairs of AGL in such a way as to establish and maintain its status as a company that is tax resident in the U.K. As a U.K. tax resident company, AGL is required to file a corporation tax return with Her Majesty’s Revenue & Customs (“HMRC”).  AGL is subject to U.K. corporation tax in respect of its worldwide profits (both income and capital gains), subject to any applicable exemptions. AGL has also registered in the U.K. to report its Value Added Tax (“VAT”) liability. The current rate of VAT is 20%. Assured Guaranty does not expect that becoming U.K. tax resident will result in any material change in the group’s overall tax charge.  Assured Guaranty expects that the dividends AGL receives from its direct subsidiaries will be exempt from U.K. corporation tax due to the exemption in section 931D of the U.K. Corporation Tax Act 2009.  In addition, any dividends paid by AGL to its shareholders should not be subject to any withholding tax in the U.K.  The U.K. government implemented a new tax regime for “controlled foreign companies” (“CFC regime”) effective January 1, 2013.  Assured Guaranty does not expect any profits of non-U.K. resident members of the group to be taxed under the CFC regime and has obtained a clearance from HMRC confirming this on the basis of current facts.
	For the periods beginning on July 1, 2009 and forward, AGMH files a consolidated federal income tax return with AGUS, AGC, AG Financial Products Inc. ("AGFP") and AG Analytics Inc. (“AGUS consolidated tax group”). Beginning on May 12, 2012, MAC also joined the AGUS consolidated tax group. Assured Guaranty Overseas US Holdings Inc. and its subsidiaries AGRO and AG Intermediary Inc., file their own consolidated federal income tax return.
	Provision for Income Taxes
	The Company's provision for income taxes for interim financial periods is not based on an estimated annual effective rate due, for example, to the variability in fair value of its credit derivatives, which prevents the Company from projecting a reliable estimated annual effective tax rate and pretax income for the full year 2015. A discrete calculation of the provision is calculated for each interim period.
	The effective tax rates reflect the proportion of income recognized by each of the Company’s operating subsidiaries, with U.S. subsidiaries taxed at the U.S. marginal corporate income tax rate of 35%, U.K. subsidiaries taxed at the U.K. blended marginal corporate tax rate of 20.25% unless subject to U.S. tax by election or as a U.S. controlled foreign corporation, and no taxes for the Company’s Bermuda subsidiaries unless subject to U.S. tax by election or as a U.S. controlled foreign corporation. For periods subsequent to April 1, 2015, the U.K. corporation tax rate has been reduced to 20%, for the period April 1, 2014 to April 1, 2015 the U.K. corporation tax rate was 21% resulting in a blended tax rate of 20.25% in 2015, and prior to April 1, 2014, the U.K. corporation tax rate was 23% resulting in a blended tax rate of 21.5% in 2014. The Company’s overall effective tax rate fluctuates based on the distribution of income across jurisdictions.
	A reconciliation of the difference between the provision for income taxes and the expected tax provision at statutory rates in taxable jurisdictions is presented below.
	Effective Tax Rate Reconciliation
		First Quarter
		2015			2014
		(in millions)
	Expected tax provision (benefit) at statutory rates in taxable jurisdictions	$	77		$	38
	Tax-exempt interest	(14		)	(14		)
	Change in liability for uncertain tax positions	1			1
	Other	1			2
	Total provision (benefit) for income taxes	$	65		$	27
	Effective tax rate	24.2		%	38.8		%
	The expected tax provision at statutory rates in taxable jurisdictions is calculated as the sum of pretax income in each jurisdiction multiplied by the statutory tax rate of the jurisdiction by which it will be taxed. Pretax income of the Company’s subsidiaries which are not U.S. or U.K. domiciled but are subject to U.S. or U.K. tax by election, establishment of tax residency or as controlled foreign corporations, are included at the U.S. or U.K. statutory tax rate. Where there is a pretax loss in one jurisdiction and pretax income in another, the total combined expected tax rate may be higher or lower than any of the individual statutory rates.
	The following table presents pretax income and revenue by jurisdiction.
	Pretax Income (Loss) by Tax Jurisdiction
		First Quarter
		2015			2014
		(in millions)
	United States	$	223		$	113
	Bermuda	50			(37		)
	U.K.	(7		)	(7		)
	Total	$	266		$	69
	Revenue by Tax Jurisdiction
		First Quarter
		2015			2014
		(in millions)
	United States	$	300		$	195
	Bermuda	73			1
	U.K.	(4		)	(1		)
	Total	$	369		$	195
	Pretax income by jurisdiction may be disproportionate to revenue by jurisdiction to the extent that insurance losses incurred are disproportionate.
	Valuation Allowance
	The Company came to the conclusion that it is more likely than not that its net deferred tax asset will be fully realized after weighing all positive and negative evidence available as required under GAAP. The positive evidence that was considered included the cumulative operating income the Company has earned over the last three years, and the significant unearned premium income to be included in taxable income. The positive evidence outweighs any negative evidence that exists. As such, the Company believes that no valuation allowance is necessary in connection with this deferred tax asset. The Company will continue to analyze the need for a valuation allowance on a quarterly basis.
	Audits
	AGUS has open tax years with the U.S. Internal Revenue Service (“IRS”) for 2009 forward and is currently under audit for the 2009-2012 tax years. The IRS concluded its field work with respect to tax years 2006 through 2008 without adjustment. On February 20, 2013 the IRS notified AGUS that the Joint Committee on Taxation completed its review of the 2006 through 2008 tax years and has accepted the results of the IRS examination without exception. Assured Guaranty Oversees US Holdings Inc. has open tax years of 2010 forward. The IRS concluded its field work with respect to tax year through 2009 for AGMH and subsidiaries while members of the Dexia Holdings Inc. consolidated tax group without adjustment. The Company's U.K. subsidiaries are not currently under examination and have open tax years of 2012 forward.
	Uncertain Tax Positions
	The Company's policy is to recognize interest and penalties related to uncertain tax positions in income tax expense and has accrued $0.5 million for First Quarter 2015 and $1 million for 2014. As of March 31, 2015 and December 31, 2014, the Company has accrued $5 million and $4.5 million of interest, respectively.
	The total amount of unrecognized tax benefits as of March 31, 2015 and December 31, 2014, that would affect the effective tax rate, if recognized, was $29 million and $28 million, respectively.

Reinsurance_and_Other_Monoline

Reinsurance and Other Monoline Exposures	3 Months Ended
	Mar. 31, 2015
Insurance [Abstract]
Reinsurance and Other Monoline Exposures	Reinsurance and Other Monoline Exposures
	The Company assumes exposure on insured obligations (“Assumed Business”) and cedes portions of its exposure on obligations it has insured (“Ceded Business”) in exchange for premiums, net of ceding commissions. The Company has historically entered into ceded reinsurance contracts in order to obtain greater business diversification and reduce the net potential loss from large risks.
	Assumed and Ceded Business
	The Company assumes business from other monoline financial guaranty companies. Under these relationships, the Company assumes a portion of the ceding company’s insured risk in exchange for a premium. The Company may be exposed to risk in this portfolio in that the Company may be required to pay losses without a corresponding premium in circumstances where the ceding company is experiencing financial distress and is unable to pay premiums. The Company’s facultative and treaty agreements are generally subject to termination at the option of the ceding company:
	•	if the Company fails to meet certain financial and regulatory criteria and to maintain a specified minimum financial strength rating, or
	•	upon certain changes of control of the Company.
	Upon termination under these conditions, the Company may be required (under some of its reinsurance agreements) to return to the ceding company unearned premiums (net of ceding commissions) and loss reserves calculated on a statutory basis of accounting, attributable to reinsurance assumed pursuant to such agreements after which the Company would be released from liability with respect to the Assumed Business.
	Upon the occurrence of the conditions set forth in the first bullet above, whether or not an agreement is terminated, the Company may be required to obtain a letter of credit or alternative form of security to collateralize its obligation to perform under such agreement or it may be obligated to increase the level of ceding commission paid.
	The downgrade of the financial strength ratings of AG Re or of AGC gives certain ceding companies the right to recapture business they had ceded to AG Re and AGC, which would lead to a reduction in the Company's unearned premium reserve and related earnings on such reserve. With respect to a significant portion of the Company's in-force financial guaranty assumed business, based on AG Re's and AGC's current ratings and subject to the terms of each reinsurance agreement, the third party ceding company may have the right to recapture business it had ceded to AG Re and/or AGC, and in connection therewith, to receive payment from AG Re or AGC of an amount equal to the statutory unearned premium (net of ceding commissions) and statutory loss reserves (if any) associated with that business, plus, in certain cases, an additional ceding commission. As of March 31, 2015, if each third party insurer ceding business to AG Re and/or AGC had a right to recapture such business, and chose to exercise such right, the aggregate amounts that AG Re and AGC could be required to pay to all such companies would be approximately $81 million and $48 million, respectively.
	The Company has Ceded Business to non-affiliated companies to limit its exposure to risk. Under these relationships, the Company cedes a portion of its insured risk in exchange for a premium paid to the reinsurer. The Company remains primarily liable for all risks it directly underwrites and is required to pay all gross claims. It then seeks reimbursement from the reinsurer for its proportionate share of claims. The Company may be exposed to risk for this exposure if it were required to pay the gross claims and not be able to collect ceded claims from an assuming company experiencing financial distress. A number of the financial guaranty insurers to which the Company has ceded par have experienced financial distress and been downgraded by the rating agencies as a result. In addition, state insurance regulators have intervened with respect to some of these insurers. The Company’s ceded contracts generally allow the Company to recapture Ceded Business after certain triggering events, such as reinsurer downgrades.
	In First Quarter 2014, the Company entered into commutation agreements to reassume previously ceded business consisting of approximately $856 million par of almost exclusively U.S. public finance and European (predominantly UK) utility and infrastructure exposures outstanding as of February 28, 2014. For such reassumptions, the Company received the statutory unearned premium outstanding as of the commutation dates plus, in one case, a commutation premium. There were no commutations in First Quarter 2015.
	The following table presents the components of premiums and losses reported in the consolidated statement of operations and the contribution of the Company's Assumed and Ceded Businesses.
	Effect of Reinsurance on Statement of Operations
		First Quarter
		2015				2014
		(in millions)
	Premiums Written:
	Direct	$	29			$	31
	Assumed(1)	3				(1		)
	Ceded	0				(24		)
	Net	$	32			$	6
	Premiums Earned:
	Direct	$	148			$	140
	Assumed	10				11
	Ceded	(16		)		(19		)
	Net	$	142			$	132
	Loss and LAE:
	Direct	$	26			$	34
	Assumed	(7		)		6
	Ceded	(1		)		1
	Net	$	18			$	41
	____________________
	-1	Negative assumed premiums written were due to change in expected Debt Service schedules.
	Other Monoline Exposures
	In addition to assumed and ceded reinsurance arrangements, the Company may also have exposure to some financial guaranty reinsurers (i.e., monolines) in other areas. Second-to-pay insured par outstanding represents transactions the Company has insured that were previously insured by other monolines. The Company underwrites such transactions based on the underlying insured obligation without regard to the primary insurer. Another area of exposure is in the investment portfolio where the Company holds fixed-maturity securities that are wrapped by monolines and whose value may decline based on the rating of the monoline. As of March 31, 2015, based on fair value, the Company had fixed-maturity securities in its investment portfolio consisting of $291 million insured by National Public Finance Guarantee Corporation ("NPFGC"), $247 million insured by Ambac Assurance Corporation ("Ambac") and $32 million insured by other guarantors.
	Exposure by Reinsurer
			Ratings at				Par Outstanding (1)
			May 6, 2015				As of March 31, 2015
	Reinsurer		Moody’s		S&P		Ceded Par			Second-to-			Assumed Par
			Reinsurer		Reinsurer		Outstanding			Pay Insured			Outstanding
			Rating		Rating					Par
										Outstanding
			(dollars in millions)
	American Overseas Reinsurance Company Limited (f/k/a Ram Re)		WR (2)		WR		$	6,363		$	—		$	30
	Tokio Marine & Nichido Fire Insurance Co., Ltd.		Aa3 (3)		AA- (3)		5,006			—			—
	Radian Asset (4)		WR		NR		3,984			18			620
	Syncora Guarantee Inc.		WR		WR		3,522			1,451			160
	Mitsui Sumitomo Insurance Co. Ltd.		A1		A+ (3)		1,995			—			—
	ACA Financial Guaranty Corp.		NR (5)		WR		745			1			—
	Swiss Reinsurance Co.		Aa3		AA-		91			—			—
	Ambac		WR		WR		82			4,796			13,281
	NPFGC (6)		A3		AA-		—			6,061			5,724
	MBIA		-7		-7		—			2,465			484
	Financial Guaranty Insurance Co.		WR		WR		—			2,008			809
	Ambac Assurance Corp. Segregated Account		NR		NR		—			105			936
	CIFG Assurance North America Inc.		WR		WR		—			102			4,177
	Other		Various		Various		199			804			45
	Total						$	21,987		$	17,811		$	26,266
	____________________
	-1	Includes par related to insured credit derivatives.
	(2)    Represents “Withdrawn Rating.”
	(3)    The Company has structural collateral agreements satisfying the triple-A credit requirement of S&P and/or Moody’s.
	-4	On April 1, 2015, AGC consummated the acquisition of Radian Asset and merged Radian Asset with and into AGC, with AGC as the surviving company of the merger.
	(5)    Represents “Not Rated.”
-6	NPFGC is rated AA+ by KBRA.
-7	MBIA includes subsidiaries MBIA Insurance Corp. rated B by S&P and B2 by Moody's and MBIA U.K. Insurance Ltd. rated B by S&P and Ba2 by Moody’s.
Amounts Due (To) From Reinsurers
As of March 31, 2015
	Assumed				Ceded			Assumed			Ceded
	Premium, net				Premium, net			Expected			Expected
	of Commissions				of Commissions			Loss and LAE			Loss and LAE
	(in millions)
American Overseas Reinsurance Company Limited (f/k/a Ram Re)	$	—			$	(7	)	$	—		$	10
Tokio Marine & Nichido Fire Insurance Co., Ltd.	—				(12		)	—			45
Radian Asset	—				(12		)	—			18
Syncora Guarantee Inc.	—				(27		)	—			4
Mitsui Sumitomo Insurance Co. Ltd.	—				(3		)	—			14
Swiss Reinsurance Co.	—				(2		)	—			6
Ambac	43				—			(18		)	—
Ambac Assurance Corp. Segregated Account	12				—			(77		)	—
CIFG Assurance North America Inc.	—				—			(7		)	—
MBIA	6				—			(10		)	—
NPFGC	6				—			(7		)	—
Financial Guaranty Insurance Co.	4				—			(2		)	—
Other	2				(4		)	—			—
Total	$	73			$	(67	)	$	(121	)	$	97
Excess of Loss Reinsurance Facility
AGC, AGM and MAC entered into an aggregate excess of loss reinsurance facility with a number of reinsurers, effective as of January 1, 2014. Currently, the facility covers losses occurring from January 1, 2015 through December 31, 2021, subject to the payment of certain additional premium by AGC, AGM and MAC on or before January 1, 2016.  If AGC, AGM and MAC elect not to pay such additional premium, the facility terminates on January 1, 2016. The facility covers certain U.S. public finance credits insured or reinsured by AGC, AGM and MAC as of September 30, 2013, excluding credits that were rated non-investment grade as of December 31, 2013 by Moody’s or S&P or internally by AGC, AGM or MAC and is subject to certain per credit limits. Among the credits excluded are those associated with the Commonwealth of Puerto Rico and its related authorities and public corporations. The facility attaches when AGC’s, AGM’s and MAC’s net losses (net of AGC’s and AGM's reinsurance (including from affiliates) and net of recoveries) exceed $1.5 billion in the aggregate. The facility covers a portion of the next $500 million of losses, with the reinsurers assuming pro rata in the aggregate $450 million of the $500 million of losses and AGC, AGM and MAC jointly retaining the remaining $50 million of losses. The reinsurers are required to be rated at least AA- or to post collateral sufficient to provide AGM, AGC and MAC with the same reinsurance credit as reinsurers rated AA-. AGM, AGC and MAC are obligated to pay the reinsurers their share of recoveries relating to losses during the coverage period in the covered portfolio. AGC, AGM and MAC paid approximately $19 million of premiums for the term January 1, 2014 through December 31, 2014 and also paid approximately $19 million of premiums for the term January 1, 2015 through December 31, 2015.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	Legal Proceedings
	Lawsuits arise in the ordinary course of the Company’s business. It is the opinion of the Company’s management, based upon the information available, that the expected outcome of litigation against the Company, individually or in the aggregate, will not have a material adverse effect on the Company’s financial position or liquidity, although an adverse resolution of litigation against the Company in a fiscal quarter or year could have a material adverse effect on the Company’s results of operations in a particular quarter or year.
	The Company establishes accruals for litigation and regulatory matters to the extent it is probable that a loss has been incurred and the amount of that loss can be reasonably estimated. For litigation and regulatory matters where a loss may be reasonably possible, but not probable, or is probable but not reasonably estimable, no accrual is established, but if the matter is material, it is disclosed, including matters discussed below. The Company reviews relevant information with respect to its litigation and regulatory matters on a quarterly, and annual basis and updates its accruals, disclosures and estimates of reasonably possible loss based on such reviews.
	In addition, in the ordinary course of their respective businesses, certain of the Company’s subsidiaries assert claims in legal proceedings against third parties to recover losses paid in prior periods. For example, as described in the "Recovery Litigation" section of Note 5, Expected Loss to be Paid, in December 2008, the Company filed a claim in the Supreme Court of the State of New York against an investment manager in a transaction it insured alleging breach of fiduciary duty, gross negligence and breach of contract; discovery on the matter is ongoing. In the past, AGC and AGM have filed complaints against certain sponsors and underwriters of RMBS securities that AGC or AGM had insured, alleging that such persons had breached representations and warranties in the transaction documents, failed to cure or repurchase defective loans and/or violated state securities laws. The amounts, if any, the Company will recover in proceedings to recover losses are uncertain, and recoveries, or failure to obtain recoveries, in any one or more of these proceedings during any quarter or year could be material to the Company’s results of operations in that particular quarter or year.
	Litigation
	Proceedings Relating to the Company’s Financial Guaranty Business
	The Company receives subpoenas duces tecum and interrogatories from regulators from time to time.
	On November 28, 2011, Lehman Brothers International (Europe) (in administration) (“LBIE”) sued AGFP, an affiliate of AGC which in the past had provided credit protection to counterparties under credit default swaps. AGC acts as the credit support provider of AGFP under these credit default swaps. LBIE’s complaint, which was filed in the Supreme Court of the State of New York, alleged that AGFP improperly terminated nine credit derivative transactions between LBIE and AGFP and improperly calculated the termination payment in connection with the termination of 28 other credit derivative transactions between LBIE and AGFP. Following defaults by LBIE, AGFP properly terminated the transactions in question in compliance with the requirements of the agreement between AGFP and LBIE, and calculated the termination payment. AGFP calculated that LBIE owes AGFP approximately $30 million in connection with the termination of the credit derivative transactions, whereas LBIE asserted in the complaint that AGFP owes LBIE a termination payment of approximately $1.4 billion. On February 3, 2012, AGFP filed a motion to dismiss certain of the counts in the complaint, and on March 15, 2013, the court granted AGFP's motion to dismiss the count relating to improper termination of the nine credit derivative transactions and denied AGFP's motion to dismiss the count relating to the remaining transactions. In their April 10, 2015 report to LBIE’s unsecured creditors, LBIE’s administrators disclosed that LBIE's valuation expert has calculated LBIE's damages in aggregate for the 28 transactions to range between a minimum of approximately $200 million and a maximum of approximately $500 million, depending on what adjustment, if any, is made for AGFP's credit risk and excluding any applicable interest. Discovery has been ongoing and motions for summary judgment are due in September 2015. The Company cannot reasonably estimate the possible loss, if any, that may arise from this lawsuit.
	On September 25, 2013, Wells Fargo Bank, N.A., as trust administrator of the MASTR Adjustable Rate Mortgages Trust 2007-3, filed an interpleader complaint in the U.S. District Court for the Southern District of New York against AGM, among others, relating to the right of AGM to be reimbursed from certain cashflows for principal claims paid in respect of insured certificates. The Company estimates that an adverse outcome to the interpleader proceeding could increase losses on the transaction by approximately $10 - $20 million, net of expected settlement payments and reinsurance in force.
	On May 28, 2014, Houston Casualty Company Europe, Seguros y Reseguros, S.A. (“HCCE”) notified Radian Asset that it was demanding arbitration against Radian Asset in connection with housing cooperative losses presented to Radian Asset by HCCE under several years of quota-share surety reinsurance contracts.  HCCE claims AGC, as successor to Radian Asset, is required to pay to it, as ceding company, among other amounts, its share of certain current and future housing cooperative losses, together with certain fees, expenses and costs relating thereto.  HCCE has presented approximately €14 million in claims to AGC through March 31, 2015.  HCCE is still in the process of settling additional similar claims, so the aggregate ultimate amount the ceding company will claim is uncertain. The reinsurance contract provides for arbitration in Madrid and is governed by Spanish law.  Arbitration proceedings may commence in 2015.‎
	Proceedings Resolved Since December 31, 2014
	On November 19, 2012, Lehman Brothers Holdings Inc. (“LBHI”) and Lehman Brothers Special Financing Inc. (“LBSF") commenced an adversary complaint and claim objection in the United States Bankruptcy Court for the Southern District of New York against Credit Protection Trust 283 (“CPT 283”), FSA Administrative Services, LLC, as trustee for CPT 283, and AGM, in connection with CPT 283's termination of a CDS between LBSF and CPT 283. CPT 283 terminated the CDS as a consequence of LBSF failing to make a scheduled payment owed to CPT 283, which termination occurred after LBHI filed for bankruptcy but before LBSF filed for bankruptcy. The CDS provided that CPT 283 was entitled to receive from LBSF a termination payment in that circumstance of approximately $43.8 million (representing the economic equivalent of the future fixed payments CPT 283 would have been entitled to receive from LBSF had the CDS not been terminated), and CPT 283 filed proofs of claim against LBSF and LBHI (as LBSF's credit support provider) for such amount. LBHI and LBSF sought to disallow and expunge (as impermissible and unenforceable penalties) CPT 283's proofs of claim against LBHI and LBSF and recover approximately $67.3 million, which LBHI and LBSF allege was the mark-to-market value of the CDS to LBSF (less unpaid amounts) on the day CPT 283 terminated the CDS, plus interest, attorney's fees, costs and other expenses. On the same day, LBHI and LBSF also commenced an adversary complaint and claim objection against Credit Protection Trust 207 (“CPT 207”), FSA Administrative Services, LLC, as trustee for CPT 207, and AGM, in connection with CPT 207's termination of a CDS between LBSF and CPT 207. Similarly, the CDS provided that CPT 207 was entitled to receive from LBSF a termination payment in that circumstance of $492,555. LBHI and LBSF seek to disallow and expunge CPT 207's proofs of claim against LBHI and LBSF and recover approximately $1.5 million. On January 30, 2015, the parties signed an agreement pursuant to which LBHI and LBSF dismissed their litigation related to CPT 283's and CPT 207's CDS terminations and the parties agreed that CPT 283 and CPT 207 have a total allowed claim in bankruptcy against LBSF and LBHI of $20 million.
	Proceedings Related to AGMH’s Former Financial Products Business
	The following is a description of legal proceedings involving AGMH’s former Financial Products Business. Although the Company did not acquire AGMH’s former Financial Products Business, which included AGMH’s former GIC business, medium term notes business and portions of the leveraged lease businesses, certain legal proceedings relating to those businesses are against entities that the Company did acquire. While Dexia SA and Dexia Crédit Local S.A., jointly and severally, have agreed to indemnify the Company against liability arising out of the proceedings described below, such indemnification might not be sufficient to fully hold the Company harmless against any injunctive relief or civil or criminal sanction that is imposed against AGMH or its subsidiaries.
	Governmental Investigations into Former Financial Products Business
	AGMH and/or AGM have received subpoenas duces tecum and interrogatories or civil investigative demands from the Attorneys General of the States of Connecticut, Florida, Illinois, Massachusetts, Missouri, New York, Texas and West Virginia relating to their investigations of alleged bid rigging of municipal GICs. AGMH has been responding to such requests. AGMH may receive additional inquiries from these or other regulators and expects to provide additional information to such regulators regarding their inquiries in the future. In addition,
	•	AGMH received a subpoena from the Antitrust Division of the Department of Justice in November 2006 issued in connection with an ongoing criminal investigation of bid rigging of awards of municipal GICs and other municipal derivatives; and
	•	AGM received a subpoena from the SEC in November 2006 related to an ongoing industry-wide investigation concerning the bidding of municipal GICs and other municipal derivatives.
	Pursuant to the subpoenas, AGMH has furnished to the Department of Justice and SEC records and other information with respect to AGMH’s municipal GIC business. The ultimate loss that may arise from these investigations remains uncertain.
	Lawsuits Relating to Former Financial Products Business
	During 2008, nine putative class action lawsuits were filed in federal court alleging federal antitrust violations in the municipal derivatives industry, seeking damages and alleging, among other things, a conspiracy to fix the pricing of, and manipulate bids for, municipal derivatives, including GICs. These cases have been coordinated and consolidated for pretrial proceedings in the U.S. District Court for the Southern District of New York as MDL 1950, In re Municipal Derivatives Antitrust Litigation, Case No. 1:08-cv-2516 (“MDL 1950”). Five of these cases named both AGMH and AGM: (a) Hinds County, Mississippi v. Wachovia Bank, N.A.; (b) Fairfax County, Virginia v. Wachovia Bank, N.A.; (c) Central Bucks School District, Pennsylvania v. Wachovia Bank, N.A.; (d) Mayor and City Council of Baltimore, Maryland v. Wachovia Bank, N.A.; and (e) Washington County, Tennessee v. Wachovia Bank, N.A. In April 2009, the MDL 1950 court granted the defendants’ motion to dismiss on the federal claims, but granted leave for the plaintiffs to file an amended complaint. The Corrected Third Consolidated Amended Class Action Complaint, filed on October 9, 2013, lists neither AGM nor AGMH as a named defendant or a co-conspirator. The complaint generally seeks unspecified monetary damages, interest, attorneys’ fees and other costs. The other four cases named AGMH (but not AGM) and also alleged that the defendants violated California state antitrust law and common law by engaging in illegal bid-rigging and market allocation, thereby depriving the cities or municipalities of competition in the awarding of GICs and ultimately resulting in the cities paying higher fees for these products: (f) City of Oakland, California v. AIG Financial Products Corp.; (g) County of Alameda, California v. AIG Financial Products Corp.; (h) City of Fresno, California v. AIG Financial Products Corp.; and (i) Fresno County Financing Authority v. AIG Financial Products Corp. When the four plaintiffs filed a consolidated complaint in September 2009, the plaintiffs did not name AGMH as a defendant. However, the complaint does describe some of AGMH’s and AGM’s activities. The consolidated complaint generally seeks unspecified monetary damages, interest, attorneys’ fees and other costs. In April 2010, the MDL 1950 court granted in part and denied in part the named defendants’ motions to dismiss this consolidated complaint. The Company cannot reasonably estimate the possible loss, if any, or range of loss that may arise from these lawsuits.
	In 2008, AGMH and AGM also were named in five non-class action lawsuits originally filed in the California Superior Courts alleging violations of California law related to the municipal derivatives industry: (a) City of Los Angeles, California v. Bank of America, N.A.; (b) City of Stockton, California v. Bank of America, N.A.; (c) County of San Diego, California v. Bank of America, N.A.; (d) County of San Mateo, California v. Bank of America, N.A.; and (e) County of Contra Costa, California v. Bank of America, N.A. Amended complaints in these actions were filed in September 2009, adding a federal antitrust claim and naming AGM (but not AGMH) and AGUS, among other defendants. These cases have been transferred to the Southern District of New York and consolidated with MDL 1950 for pretrial proceedings. In late 2009, AGM and AGUS, among other defendants, were named in six additional non-class action cases filed in federal court, which also have been coordinated and consolidated for pretrial proceedings with MDL 1950: (f) City of Riverside, California v. Bank of America, N.A.; (g) Sacramento Municipal Utility District v. Bank of America, N.A.; (h) Los Angeles World Airports v. Bank of America, N.A.; (i) Redevelopment Agency of the City of Stockton v. Bank of America, N.A.; (j) Sacramento Suburban Water District v. Bank of America, N.A.; and (k) County of Tulare, California v. Bank of America, N.A. The MDL 1950 court denied AGM and AGUS’s motions to dismiss these eleven complaints in April 2010. Amended complaints were filed in May 2010. On October 29, 2010, AGM and AGUS were voluntarily dismissed with prejudice from the Sacramento Municipal Utility District case only. The complaints in these lawsuits generally seek or sought unspecified monetary damages, interest, attorneys’ fees, costs and other expenses. The Company cannot reasonably estimate the possible loss, if any, or range of loss that may arise from the remaining lawsuits.
	In May 2010, AGM and AGUS, among other defendants, were named in five additional non-class action cases filed in federal court in California: (a) City of Richmond, California v. Bank of America, N.A. (filed on May 18, 2010, N.D. California); (b) City of Redwood City, California v. Bank of America, N.A. (filed on May 18, 2010, N.D. California); (c) Redevelopment Agency of the City and County of San Francisco, California v. Bank of America, N.A. (filed on May 21, 2010, N.D. California); (d) East Bay Municipal Utility District, California v. Bank of America, N.A. (filed on May 18, 2010, N.D. California); and (e) City of San Jose and the San Jose Redevelopment Agency, California v. Bank of America, N.A (filed on May 18, 2010, N.D. California). These cases have also been transferred to the Southern District of New York and consolidated with MDL 1950 for pretrial proceedings. In September 2010, AGM and AGUS, among other defendants, were named in a sixth additional non-class action filed in federal court in New York, but which alleges violation of New York’s Donnelly Act in addition to federal antitrust law: Active Retirement Community, Inc. d/b/a Jefferson’s Ferry v. Bank of America, N.A. (filed on September 21, 2010, E.D. New York), which has also been transferred to the Southern District of New York and consolidated with MDL 1950 for pretrial proceedings. In December 2010, AGM and AGUS, among other defendants, were named in a seventh additional non-class action filed in federal court in the Central District of California, Los Angeles Unified School District v. Bank of America, N.A., and in an eighth additional non-class action filed in federal court in the Southern District of New York, Kendal on Hudson, Inc. v. Bank of America, N.A. These cases also have been consolidated with MDL 1950 for pretrial proceedings. The complaints in these lawsuits generally seek unspecified monetary damages, interest, attorneys’ fees, costs and other expenses. The Company cannot reasonably estimate the possible loss, if any, or range of loss that may arise from these lawsuits.
	In January 2011, AGM and AGUS, among other defendants, were named in an additional non-class action case filed in federal court in New York, which alleges violation of New York’s Donnelly Act in addition to federal antitrust law: Peconic Landing at Southold, Inc. v. Bank of America, N.A. This case has been consolidated with MDL 1950 for pretrial proceedings. The complaint in this lawsuit generally seeks unspecified monetary damages, interest, attorneys’ fees, costs and other expenses. The Company cannot reasonably estimate the possible loss, if any, or range of loss that may arise from this lawsuit.
	In September 2009, the Attorney General of the State of West Virginia filed a lawsuit (Circuit Ct. Mason County, W. Va.) against Bank of America, N.A. alleging West Virginia state antitrust violations in the municipal derivatives industry, seeking damages and alleging, among other things, a conspiracy to fix the pricing of, and manipulate bids for, municipal derivatives, including GICs. An amended complaint in this action was filed in June 2010, adding a federal antitrust claim and naming AGM (but not AGMH) and AGUS, among other defendants. This case has been removed to federal court as well as transferred to the S.D.N.Y. and consolidated with MDL 1950 for pretrial proceedings. AGM and AGUS answered West Virginia's Second Amended Complaint on November 11, 2013. The complaint in this lawsuit generally seeks civil penalties, unspecified monetary damages, interest, attorneys’ fees, costs and other expenses. The Company cannot reasonably estimate the possible loss, if any, or range of loss that may arise from this lawsuit.

LongTerm_Debt_and_Credit_Facil

Long-Term Debt and Credit Facilities	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Long-Term Debt and Credit Facilities	Long-Term Debt and Credit Facilities
	The principal and carrying values of the Company’s long-term debt are presented in the table below.
	Principal and Carrying Amounts of Debt
		As of March 31, 2015				As of December 31, 2014
		Principal		Carrying		Principal		Carrying
				Value				Value
		(in millions)
	AGUS:
	7.0% Senior Notes	$	200	$	198	$	200	$	198
	5.0% Senior Notes	500		499		500		499
	Series A Enhanced Junior Subordinated Debentures	150		150		150		150
	Total AGUS	850		847		850		847
	AGMH:
	67/8% QUIBS	100		68		100		68
	6.25% Notes	230		139		230		139
	5.60% Notes	100		55		100		55
	Junior Subordinated Debentures	300		177		300		175
	Total AGMH	730		439		730		437
	AGM:
	Notes Payable	15		18		16		19
	Total AGM	15		18		16		19
	Total	$	1,595	$	1,304	$	1,596	$	1,303
	Recourse Credit Facilities
	2009 Strip Coverage Facility
	In connection with the Company's acquisition of AGMH and its subsidiaries from Dexia Holdings Inc., AGM agreed to retain the risks relating to the debt and strip policy portions of the leveraged lease business. The liquidity risk to AGM related to the strip policy portion of the leveraged lease business is mitigated by the strip coverage facility described below.
	In a leveraged lease transaction, a tax-exempt entity (such as a transit agency) transfers tax benefits to a tax-paying entity by transferring ownership of a depreciable asset, such as subway cars. The tax-exempt entity then leases the asset back from its new owner.
	If the lease is terminated early, the tax-exempt entity must make an early termination payment to the lessor. A portion of this early termination payment is funded from monies that were pre-funded and invested at the closing of the leveraged lease transaction (along with earnings on those invested funds). The tax-exempt entity is obligated to pay the remaining, unfunded portion of this early termination payment (known as “strip coverage”) from its own sources. AGM issued financial guaranty insurance policies (known as “strip policies”) that guaranteed the payment of these unfunded strip coverage amounts to the lessor, in the event that a tax-exempt entity defaulted on its obligation to pay this portion of its early termination payment. AGM can then seek reimbursement of its strip policy payments from the tax-exempt entity, and can also sell the transferred depreciable asset and reimburse itself from the sale proceeds.
	Currently, all the leveraged lease transactions in which AGM acts as strip coverage provider are breaching a rating trigger related to AGM and are subject to early termination. However, early termination of a lease does not result in a draw on the AGM policy if the tax-exempt entity makes the required termination payment. If all the leases were to terminate early and the tax-exempt entities do not make the required early termination payments, then AGM would be exposed to possible liquidity claims on gross exposure of approximately $1.2 billion as of March 31, 2015. To date, none of the leveraged lease transactions that involve AGM has experienced an early termination due to a lease default and a claim on the AGM policy. It is difficult to determine the probability that AGM will have to pay strip provider claims or the likely aggregate amount of such claims. At March 31, 2015, approximately $1.4 billion of cumulative strip par exposure had been terminated since 2008 on a consensual basis. The consensual terminations have resulted in no claims on AGM.
	On July 1, 2009, AGM and Dexia Crédit Local S.A., acting through its New York Branch (“Dexia Crédit Local (NY)”), entered into a credit facility (the “Strip Coverage Facility”). Under the Strip Coverage Facility, Dexia Crédit Local (NY) agreed to make loans to AGM to finance all draws made by lessors on AGM strip policies that were outstanding as of November 13, 2008, up to the commitment amount. The commitment amount of the Strip Coverage Facility was $1 billion at closing of the Company's acquisition of AGMH. AGM has reduced the maximum commitment amount from time to time, after taking into account its experience with its exposure to leveraged lease transactions. Most recently, as of June 30, 2014, AGM reduced the maximum commitment amount to $495 million and agreed with Dexia Crédit Local (NY) that the commitment amount would no longer amortize on a scheduled monthly basis.
	Fundings under this facility are subject to certain conditions precedent, and their repayment is collateralized by a security interest that AGM granted to Dexia Crédit Local (NY) in amounts that AGM recovers—from the tax-exempt entity, or from asset sale proceeds—following its payment of strip policy claims. On June 30, 2014, AGM and Dexia Crédit Local (NY) agreed to shorten the duration of the facility. Accordingly, the Strip Coverage Facility will terminate upon the earliest to occur of an AGM change of control, the reduction of the commitment amount to $0 in accordance with the terms of the facility, and June 30, 2024 (rather than the original maturity date of January 31, 2042).
	The Strip Coverage Facility’s financial covenants require that AGM and its subsidiaries maintain:
	•a maximum debt-to-capital ratio of 30%; and
	•	a minimum net worth of 75% of consolidated net worth as of July 1, 2009, plus, beginning June 30, 2015 and on each anniversary of such date, an amount equal to the product of (i) 25% of the aggregate consolidated net income (or loss) for the period beginning July 2, 2009 and ending on June 30, 2014 and (ii) a fraction, the numerator of which is the commitment amount as of the relevant calculation date and the denominator of which is $1 billion.
	The Company was in compliance with all financial covenants as of March 31, 2015.
	The Strip Coverage Facility contains restrictions on AGM, including, among other things, in respect of its ability to incur debt, permit liens, pay dividends or make distributions, dissolve or become party to a merger or consolidation. Most of these restrictions are subject to exceptions. The Strip Coverage Facility has customary events of default, including (subject to certain materiality thresholds and grace periods) payment default, bankruptcy or insolvency proceedings and cross-default to other debt agreements.
	As of March 31, 2015, no amounts were outstanding under this facility, nor have there been any borrowings during the life of this facility.
	Intercompany Credit Facility and Intercompany Debt
	On October 25, 2013, AGL, as borrower, and AGUS, as lender, entered into a revolving credit facility pursuant to which AGL may, from time to time, borrow for general corporate purposes. Under the credit facility, AGUS committed to lend a principal amount not exceeding $225 million in the aggregate. Such commitment terminates on the October 25, 2018 (the “loan termination date”). The unpaid principal amount of each loan will bear interest at a fixed rate equal to 100% of the then applicable Federal short-term or mid-term interest rate, as the case may be, as determined under Internal Revenue Code Sec. 1274(d), and interest on all loans will be computed for the actual number of days elapsed on the basis of a year consisting of 360 days. Accrued interest on all loans will be paid on the last day of each June and December, beginning on December 31, 2013, and at maturity.  AGL must repay the then unpaid principal amounts of the loans by the third anniversary of the loan termination date. No amounts are currently outstanding under the credit facility.
	On March 30, 2015, AGUS loaned $200 million to AGC to facilitate the acquisition of Radian Asset on April 1, 2015. AGC repaid the loan on April 14, 2015.
	In addition, in 2012 AGUS borrowed $90 million from its affiliate Assured Guaranty Re Overseas Ltd. to fund the acquisition of MAC. That loan remained outstanding as of March 31, 2015.
	Committed Capital Securities
	On April 8, 2005, AGC entered into separate agreements (the “Put Agreements”) with four custodial trusts (each, a “Custodial Trust”) pursuant to which AGC may, at its option, cause each of the Custodial Trusts to purchase up to $50 million of perpetual preferred stock of AGC (the “AGC Preferred Stock”). The custodial trusts were created as a vehicle for providing capital support to AGC by allowing AGC to obtain immediate access to new capital at its sole discretion at any time through the exercise of the put option. If the put options were exercised, AGC would receive $200 million in return for the issuance of its own perpetual preferred stock, the proceeds of which may be used for any purpose, including the payment of claims. The put options have not been exercised through the date of this filing.
	Distributions on the AGC CCS are determined pursuant to an auction process. On April 7, 2008 this auction process failed, thereby increasing the annualized rate on the AGC CCS to one-month LIBOR plus 250 basis points. Distributions on the AGC preferred stock will be determined pursuant to the same process.
	In June 2003, $200 million of “AGM CPS”, money market preferred trust securities, were issued by trusts created for the primary purpose of issuing the AGM CPS, investing the proceeds in high-quality commercial paper and selling put options to AGM, allowing AGM to issue the trusts non-cumulative redeemable perpetual preferred stock (the “AGM Preferred Stock”) of AGM in exchange for cash. There are four trusts, each with an initial aggregate face amount of $50 million. These trusts hold auctions every 28 days, at which time investors submit bid orders to purchase AGM CPS. If AGM were to exercise a put option, the applicable trust would transfer the portion of the proceeds attributable to principal received upon maturity of its assets, net of expenses, to AGM in exchange for AGM Preferred Stock. AGM pays a floating put premium to the trusts, which represents the difference between the commercial paper yield and the winning auction rate (plus all fees and expenses of the trust). If an auction does not attract sufficient clearing bids, however, the auction rate is subject to a maximum rate of one-month LIBOR plus 200 basis points for the next succeeding distribution period. Beginning in August 2007, the AGM CPS required the maximum rate for each of the relevant trusts. AGM continues to have the ability to exercise its put option and cause the related trusts to purchase AGM Preferred Stock. The trusts provide AGM access to new capital at its sole discretion through the exercise of the put options. As of March 31, 2015 the put option had not been exercised. The Company does not consider itself to be the primary beneficiary of the trusts. See Note 7, Fair Value Measurement, –Other Assets–Committed Capital Securities, for a fair value measurement discussion.

Earnings_Per_Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share
	Computation of Earnings Per Share
		First Quarter
		2015		2014
		(in millions, except per share amounts)
	Basic earnings per share ("EPS"):
	Net income (loss) attributable to AGL	$	201	$	42
	Less: Distributed and undistributed income (loss) available to nonvested shareholders	0		0
	Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	$	201	$	42
	Basic shares	155.8		182.1
	Basic EPS	$	1.29	$	0.23
	Diluted EPS:
	Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	$	201	$	42
	Plus: Re-allocation of undistributed income (loss) available to nonvested shareholders of AGL and subsidiaries	0		—
	Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, diluted	$	201	$	42
	Basic shares	155.8		182.1
	Effect of dilutive securities:
	Options and restricted stock awards	1		1
	Diluted shares	156.8		183.1
	Diluted EPS	$	1.28	$	0.23
	Potentially dilutive securities excluded from computation of EPS because of antidilutive effect	0.7		1.5

Shareholders_Equity

Shareholders' Equity	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Shareholders' Equity	Shareholders' Equity
	Other Comprehensive Income
	The following tables present the changes in each component of AOCI and the effect of significant reclassifications out of AOCI on the respective line items in net income.
	Changes in Accumulated Other Comprehensive Income by Component
	First Quarter 2015
		Net Unrealized			Net Unrealized			Cumulative			Cash Flow Hedge			Total Accumulated
		Gains (Losses) on			Gains (Losses) on			Translation						Other
		Investments with no Other-Than-Temporary Impairment			Investments with Other-Than-Temporary Impairment			Adjustment						Comprehensive
														Income
		(in millions)
	Balance, December 31, 2014	$	367		$	4		$	(10	)	$	9		$	370
	Other comprehensive income (loss) before reclassifications	18			(2		)	(5		)	—			11
	Amounts reclassified from AOCI to:
	Net realized investment gains (losses)	(20		)	4			—			—			(16		)
	Interest expense	—			—			—			(1		)	(1		)
	Total before tax	(20		)	4			—			(1		)	(17		)
	Tax (provision) benefit	7			(1		)	—			0			6
	Total amount reclassified from AOCI, net of tax	(13		)	3			—			(1		)	(11		)
	Net current period other comprehensive income (loss)	5			1			(5		)	(1		)	0
	Balance, March 31, 2015	$	372		$	5		$	(15	)	$	8		$	370
	Changes in Accumulated Other Comprehensive Income by Component
	First Quarter 2014
		Net Unrealized			Net Unrealized			Cumulative			Cash Flow Hedge			Total Accumulated
		Gains (Losses) on			Gains (Losses) on			Translation						Other
		Investments with no Other-Than-Temporary Impairment			Investments with Other-Than-Temporary Impairment			Adjustment						Comprehensive
														Income
		(in millions)
	Balance, December 31, 2013	$	178		$	(24	)	$	(3	)	$	9		$	160
	Other comprehensive income (loss) before reclassifications	94			8			1			—			103
	Amounts reclassified from AOCI to:
	Net realized investment gains (losses)	(2		)	5			—			—			3
	Interest expense	—			—			—			0			0
	Total before tax	(2		)	5			—			0			3
	Tax (provision) benefit	1			(2		)	—			(1		)	(2		)
	Total amount reclassified from AOCI, net of tax	(1		)	3			—			(1		)	1
	Net current period other comprehensive income (loss)	93			11			1			(1		)	104
	Balance, March 31, 2014	$	271		$	(13	)	$	(2	)	$	8		$	264
	Share Repurchase
	The following table presents share repurchases by quarter since January 2013.
	Share Repurchases
	Period		Number of Shares Repurchased		Total Payments(in millions)			Average Price Paid Per Share
	2013		12,512,759		$	264		$	21.12
	2014 (January 1 - March 31)		1,350,443		35			25.92
	2014 (April 1 - June 30)		7,051,842		177			25.14
	2014 (July 1 - September 30)		9,623,309		226			23.47
	2014 (October 1 - December 31)		6,388,187		152			23.83
	Total 2014		24,413,781		590			24.17
	2015 (January 1 - March 31)		5,860,291		152			25.87
	Total 2015 (through March 31)		5,860,291		152			25.87
	2015 (April 1 - through May 8)		2,058,927		56			27.36
	Total 2015		7,919,218		208			26.26
	Cumulative repurchases since the beginning of 2013		44,845,758		$	1,062		$	23.69
	As of May 8, 2015, approximately $2 million of capacity remains from the August 6, 2014 $400 million share repurchase authorization. On May 6, 2015, AGL's Board of Directors approved the repurchase of an incremental $400 million of common shares.
	The Company expects to repurchase shares from time to time in the open market or in privately negotiated transactions. The timing, form and amount of the share repurchases under the program are at the discretion of management and will depend on a variety of factors, including free funds available at the parent company, market conditions, the Company's capital position, legal requirements and other factors. The repurchase program may be modified, extended or terminated by the Board of Directors at any time. It does not have an expiration date.

Subsidiary_Information

Subsidiary Information	3 Months Ended
	Mar. 31, 2015
Subsidiary Information [abstract]
Subsidiary Information	Subsidiary Information
	The following tables present the condensed consolidating financial information for AGUS and AGMH, wholly-owned subsidiaries of AGL, which have issued publicly traded debt securities (see Note 15, Long Term Debt and Credit Facilities). The information for AGL, AGUS and AGMH presents its subsidiaries on the equity method of accounting.
	CONDENSED CONSOLIDATING BALANCE SHEET
	AS OF MARCH 31, 2015
	(in millions)
		Assured			AGUS			AGMH			Other			Consolidating			Assured
		Guaranty Ltd.			(Issuer)			(Issuer)			Entities			Adjustments			Guaranty Ltd.
		(Parent)															(Consolidated)
	ASSETS
	Total investment portfolio and cash	$	47		$	82		$	23		$	11,347		$	(300	)	$	11,199
	Investment in subsidiaries	5,722			5,087			3,955			350			(15,114		)	—
	Premiums receivable, net of commissions payable	—			—			—			830			(130		)	700
	Ceded unearned premium reserve	—			—			—			1,430			(1,065		)	365
	Deferred acquisition costs	—			—			—			184			(64		)	120
	Reinsurance recoverable on unpaid losses	—			—			—			344			(267		)	77
	Credit derivative assets	—			—			—			262			(185		)	77
	Deferred tax asset, net	—			56			—			251			(89		)	218
	Intercompany receivable	—			200			—			90			(290		)	—
	Financial guaranty variable interest entities’ assets, at fair value	—			—			—			1,499			—			1,499
	Other	21			79			31			522			(231		)	422
	TOTAL ASSETS	$	5,790		$	5,504		$	4,009		$	17,109		$	(17,735	)	$	14,677
	LIABILITIES AND SHAREHOLDERS’ EQUITY
	Unearned premium reserves	$	—		$	—		$	—		$	5,173		$	(1,046	)	$	4,127
	Loss and LAE reserve	—			—			—			1,062			(275		)	787
	Long-term debt	—			847			439			18			—			1,304
	Intercompany payable	—			90			—			500			(590		)	—
	Credit derivative liabilities	—			—			—			1,044			(185		)	859
	Deferred tax liabilities, net	—			—			93			—			(93		)	—
	Financial guaranty variable interest entities’ liabilities, at fair value	—			—			—			1,423			—			1,423
	Other	4			23			22			702			(360		)	391
	TOTAL LIABILITIES	4			960			554			9,922			(2,549		)	8,891
	TOTAL SHAREHOLDERS’ EQUITY ATTRIBUTABLE TO ASSURED GUARANTY LTD.	5,786			4,544			3,455			6,837			(14,836		)	5,786
	Noncontrolling interest	—			—			—			350			(350		)	—
	TOTAL SHAREHOLDERS' EQUITY	5,786			4,544			3,455			7,187			(15,186		)	5,786
	TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$	5,790		$	5,504		$	4,009		$	17,109		$	(17,735	)	$	14,677
	CONDENSED CONSOLIDATING BALANCE SHEET
	AS OF DECEMBER 31, 2014
	(in millions)
		Assured			AGUS			AGMH			Other			Consolidating			Assured
		Guaranty Ltd.			(Issuer)			(Issuer)			Entities			Adjustments			Guaranty Ltd.
		(Parent)															(Consolidated)
	ASSETS
	Total investment portfolio and cash	$	126		$	204		$	47		$	11,382		$	(300	)	$	11,459
	Investment in subsidiaries	5,612			5,072			3,965			339			(14,988		)	—
	Premiums receivable, net of commissions payable	—			—			—			864			(135		)	729
	Ceded unearned premium reserve	—			—			—			1,469			(1,088		)	381
	Deferred acquisition costs	—			—			—			186			(65		)	121
	Reinsurance recoverable on unpaid losses	—			—			—			338			(260		)	78
	Credit derivative assets	—			—			—			277			(209		)	68
	Deferred tax asset, net	—			54			—			295			(89		)	260
	Intercompany receivable	—			—			—			90			(90		)	—
	Financial guaranty variable interest entities’ assets, at fair value	—			—			—			1,402			—			1,402
	Other	27			77			27			538			(242		)	427
	TOTAL ASSETS	$	5,765		$	5,407		$	4,039		$	17,180		$	(17,466	)	$	14,925
	LIABILITIES AND SHAREHOLDERS’ EQUITY
	Unearned premium reserves	$	—		$	—		$	—		$	5,328		$	(1,067	)	$	4,261
	Loss and LAE reserve	—			—			—			1,066			(267		)	799
	Long-term debt	—			847			437			19			—			1,303
	Intercompany payable	—			90			—			300			(390		)	—
	Credit derivative liabilities	—			—			—			1,172			(209		)	963
	Deferred tax liabilities, net	—			—			94			—			(94		)	—
	Financial guaranty variable interest entities’ liabilities, at fair value	—			—			—			1,419			—			1,419
	Other	7			9			16			764			(374		)	422
	TOTAL LIABILITIES	7			946			547			10,068			(2,401		)	9,167
TOTAL SHAREHOLDERS’ EQUITY ATTRIBUTABLE TO ASSURED GUARANTY LTD.	5,758			4,461			3,492			6,773			(14,726		)	5,758
Noncontrolling interest	—			—			—			339			(339		)	—
TOTAL SHAREHOLDERS’ EQUITY	5,758			4,461			3,492			7,112			(15,065		)	5,758
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$	5,765		$	5,407		$	4,039		$	17,180		$	(17,466	)	$	14,925
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS
AND COMPREHENSIVE INCOME
FOR THE THREE MONTHS ENDED MARCH 31, 2015
(in millions)
	Assured			AGUS			AGMH			Other			Consolidating			Assured
	Guaranty Ltd.			(Issuer)			(Issuer)			Entities			Adjustments			Guaranty Ltd.
	(Parent)															(Consolidated)
REVENUES
Net earned premiums	$	—		$	—		$	—		$	140		$	2		$	142
Net investment income	0			0			0			104			(3		)	101
Net realized investment gains (losses)	0			0			0			19			(3		)	16
Net change in fair value of credit derivatives:
Realized gains (losses) and other settlements	—			—			—			21			0			21
Net unrealized gains (losses)	—			—			—			103			—			103
Net change in fair value of credit derivatives	—			—			—			124			0			124
Other	—			—			—			(14		)	—			(14		)
TOTAL REVENUES	0			0			—			373			(4		)	369
EXPENSES
Loss and LAE	—			—			—			18			0			18
Amortization of deferred acquisition costs	—			—			—			6			(2		)	4
Interest expense	—			13			13			4			(5		)	25
Other operating expenses	8			0			0			48			0			56
TOTAL EXPENSES	8			13			13			76			(7		)	103
INCOME (LOSS) BEFORE INCOME TAXES AND EQUITY IN NET EARNINGS OF SUBSIDIARIES	(8		)	(13		)	(13		)	297			3			266
Total (provision) benefit for income taxes	—			5			5			(72		)	(3		)	(65		)
Equity in net earnings of subsidiaries	209			163			92			9			(473		)	—
NET INCOME (LOSS)	$	201		$	155		$	84		$	234		$	(473	)	$	201
Less: noncontrolling interest	—			—			—			9			(9		)	—
NET INCOME (LOSS) ATTRIBUTABLE TO ASSURED GUARANTY LTD.	$	201		$	155		$	84		$	225		$	(464	)	$	201
COMPREHENSIVE INCOME (LOSS)	$	201		$	134		$	80		$	233		$	(447	)	$	201
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS
AND COMPREHENSIVE INCOME
FOR THE THREE MONTHS ENDED MARCH 31, 2014
(in millions)
	Assured			AGUS			AGMH			Other			Consolidating			Assured
	Guaranty Ltd.			(Issuer)			(Issuer)			Entities			Adjustments			Guaranty Ltd.
	(Parent)															(Consolidated)
REVENUES
Net earned premiums	$	—		$	—		$	—		$	131		$	1		$	132
Net investment income	0			0			0			105			(2		)	103
Net realized investment gains (losses)	0			—			0			4			(2		)	2
Net change in fair value of credit derivatives:
Realized gains (losses) and other settlements	—			—			—			19			0			19
Net unrealized gains (losses)	—			—			—			(230		)	—			(230		)
Net change in fair value of credit derivatives	—			—			—			(211		)	0			(211		)
Other	—			—			—			169			—			169
TOTAL REVENUES	0			0			0			198			(3		)	195
EXPENSES
Loss and LAE	—			—			—			39			2			41
Amortization of deferred acquisition costs	—			—			—			6			(1		)	5
Interest expense	—			7			13			5			(5		)	20
Other operating expenses	8			0			0			53			(1		)	60
TOTAL EXPENSES	8			7			13			103			(5		)	126
INCOME (LOSS) BEFORE INCOME TAXES AND EQUITY IN NET EARNINGS OF SUBSIDIARIES	(8		)	(7		)	(13		)	95			2			69
Total (provision) benefit for income taxes	—			2			5			(33		)	(1		)	(27		)
Equity in net earnings of subsidiaries	50			87			169			8			(314		)	—
NET INCOME (LOSS)	$	42		$	82		$	161		$	70		$	(313	)	$	42
Less: noncontrolling interest	—			—			—			8			(8		)	—
NET INCOME (LOSS) ATTRIBUTABLE TO ASSURED GUARANTY LTD.	$	42		$	82		$	161		$	62		$	(305	)	$	42
COMPREHENSIVE INCOME (LOSS)	$	146		$	165		$	212		$	258		$	(635	)	$	146
CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
FOR THE THREE MONTHS ENDED MARCH 31, 2015
(in millions)
	Assured			AGUS			AGMH			Other			Consolidating			Assured
	Guaranty Ltd.			(Issuer)			(Issuer)			Entities			Adjustments			Guaranty Ltd.
	(Parent)															(Consolidated)
Net cash flows provided by (used in) operating activities	$	97		$	127		$	59		$	34		$	(294	)	$	23
Cash flows from investing activities
Fixed-maturity securities:
Purchases	—			(46		)	(6		)	(396		)	—			(448		)
Sales	—			122			11			708			—			841
Maturities	—			4			—			151			—			155
Sales (purchases) of short-term investments, net	79			43			19			279			—			420
Net proceeds from financial guaranty variable entities’ assets	—			—			—			30			—			30
Intercompany debt	—			(200		)	—			—			200			—
Investment in subsidiary	—			—			25			—			(25		)	—
Other	—			—			—			3			—			3
Net cash flows provided by (used in) investing activities	79			(77		)	49			775			175			1,001
Cash flows from financing activities
Return of capital	—			—			—			(25		)	25			—
Dividends paid	(19		)	(50		)	(108		)	(136		)	294			(19		)
Repurchases of common stock	(152		)	—			—			—			—			(152		)
Share activity under option and incentive plans	(5		)	—			—			—			—			(5		)
Net paydowns of financial guaranty variable entities’ liabilities	—			—			—			(39		)	—			(39		)
Payment of long-term debt	—			—			—			(1		)	—			(1		)
Intercompany debt	—			—			—			200			(200		)	—
Other	—			—			—			4			—			4
Net cash flows provided by (used in) financing activities	(176		)	(50		)	(108		)	3			119			(212		)
Effect of exchange rate changes	—			—			—			(2		)	—			(2		)
Increase (decrease) in cash	—			—			—			810			—			810
Cash at beginning of period	0			0			4			71			—			75
Cash at end of period	$	0		$	0		$	4		$	881		$	—		$	885
CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
FOR THE THREE MONTHS ENDED MARCH 31, 2014
(in millions)
	Assured			AGUS			AGMH			Other			Consolidating			Assured
	Guaranty Ltd.			(Issuer)			(Issuer)			Entities			Adjustments			Guaranty Ltd.
	(Parent)															(Consolidated)
Net cash flows provided by (used in) operating activities	$	58		$	0		$	(6	)	$	111		$	(62	)	$	101
Cash flows from investing activities
Fixed-maturity securities:
Purchases	—			(1		)	(3		)	(513		)	—			(517		)
Sales	—			—			—			155			—			155
Maturities	—			—			—			148			—			148
Sales (purchases) of short-term investments, net	(3		)	—			(16		)	203			—			184
Net proceeds from financial guaranty variable entities’ assets	—			—			—			286			—			286
Intercompany debt	—			—			—			—			—			—
Investment in subsidiary	—			—			25			—			(25		)	—
Other	—			—			—			19			—			19
Net cash flows provided by (used in) investing activities	(3		)	(1		)	6			298			(25		)	275
Cash flows from financing activities
Return of capital	—			—			—			(25		)	25			—
Dividends paid	(20		)	—			—			(62		)	62			(20		)
Repurchases of common stock	(35		)	—			—			—			—			(35		)
Share activity under option and incentive plans	0			—			—			—			—			0
Net paydowns of financial guaranty variable entities’ liabilities	—			—			—			(281		)	—			(281		)
Payment of long-term debt	—			—			—			(6		)	—			(6		)
Intercompany debt	—			—			—			—			—			—
Net cash flows provided by (used in) financing activities	(55		)	—			—			(374		)	87			(342		)
Effect of exchange rate changes	—			—			—			1			—			1
Increase (decrease) in cash	—			(1		)	—			36			—			35
Cash at beginning of period	0			67			0			117			—			184
Cash at end of period	$	0		$	66		$	0		$	153		$	—		$	219

Business_and_Basis_of_Presenta1

Business and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	The unaudited interim consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and, in the opinion of management, reflect all adjustments that are of a normal recurring nature, necessary for a fair statement of the financial condition, results of operations and cash flows of the Company and its consolidated financial guaranty variable interest entities (“FG VIEs”) for the periods presented. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. These unaudited interim consolidated financial statements are as of March 31, 2015 and cover the three-month period ended March 31, 2015 ("First Quarter 2015") and the three-month period ended March 31, 2014 ("First Quarter 2014"). Certain financial information that is normally included in annual financial statements prepared in accordance with GAAP, but is not required for interim reporting purposes, has been condensed or omitted. The year-end balance sheet data was derived from audited financial statements.
Consolidation	The unaudited interim consolidated financial statements include the accounts of AGL, its direct and indirect subsidiaries (collectively, the “Subsidiaries”), and its consolidated FG VIEs. Intercompany accounts and transactions between and among all consolidated entities have been eliminated.
Future Application of Accounting Standards	Future Application of Accounting Standards
	Consolidation
	In February 2015, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis, which is intended to improve certain areas of consolidation guidance for legal entities such as limited partnerships, limited liability companies, and securitization structures. The ASU will be effective on January 1, 2016. Early adoption is permitted, including adoption in an interim period. The Company does not expect that ASU 2015-02 will have any material effect on its Consolidated Financial Statements.
	Interest
	In April 2015, the FASB issued ASU No. 2015-03, Interest - Imputation of Interest (Topic 835-30): Simplifying the Presentation of Debt Issuance Costs, which requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The ASU will be effective on January 1, 2016 and should be applied retrospectively. The adoption of this ASU will require the Company to reclassify its debt issuance costs from other assets to long-term debt on the Consolidated Balance Sheet.
Fair Value of Financial Instruments	The Company carries a significant portion of its assets and liabilities at fair value. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (i.e., exit price). The price represents the price available in the principal market for the asset or liability. If there is no principal market, then the price is based on a hypothetical market that maximizes the value received for an asset or minimizes the amount paid for a liability (i.e., the most advantageous market).
	Fair value is based on quoted market prices, where available. If listed prices or quotes are not available, fair value is based on either internally developed models that primarily use, as inputs, market-based or independently sourced market parameters, including but not limited to yield curves, interest rates and debt prices or with the assistance of an independent third-party using a discounted cash flow approach and the third party’s proprietary pricing models. In addition to market information, models also incorporate transaction details, such as maturity of the instrument and contractual features designed to reduce the Company’s credit exposure, such as collateral rights as applicable.
	Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments include amounts to reflect counterparty credit quality, the Company’s creditworthiness and constraints on liquidity. As markets and products develop and the pricing for certain products becomes more or less transparent, the Company may refine its methodologies and assumptions. During First Quarter 2015, no changes were made to the Company’s valuation models that had or are expected to have, a material impact on the Company’s consolidated balance sheets or statements of operations and comprehensive income.
	The Company’s methods for calculating fair value produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. The use of different methodologies or assumptions to determine fair value of certain financial instruments could result in a different estimate of fair value at the reporting date.
	The fair value hierarchy is determined based on whether the inputs to valuation techniques used to measure fair value are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect Company estimates of market assumptions. The fair value hierarchy prioritizes model inputs into three broad levels as follows, with Level 1 being the highest and Level 3 the lowest. An asset or liability’s categorization within the fair value hierarchy is based on the lowest level of significant input to its valuation.
	Level 1—Quoted prices for identical instruments in active markets. The Company generally defines an active market as a market in which trading occurs at significant volumes. Active markets generally are more liquid and have a lower bid-ask spread than an inactive market.
	Level 2—Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and observable inputs other than quoted prices, such as interest rates or yield curves and other inputs derived from or corroborated by observable market inputs.
	Level 3—Model derived valuations in which one or more significant inputs or significant value drivers are unobservable. Financial instruments are considered Level 3 when their values are determined using pricing models, discounted cash flow methodologies or similar techniques and at least one significant model assumption or input is unobservable. Level 3 financial instruments also include those for which the determination of fair value requires significant management judgment or estimation.
	Transfers between Levels 1, 2 and 3 are recognized at the end of the period when the transfer occurs. The Company reviews the classification between Levels 1, 2 and 3 quarterly to determine whether a transfer is necessary.
Consolidation, Variable Interest Entity	As part of the terms of its financial guaranty contracts, the Company obtains certain protective rights with respect to the VIE that are triggered by the occurrence of certain events, such as failure to be in compliance with a covenant due to poor deal performance or a deterioration in a servicer or collateral manager's financial condition. At deal inception, the Company typically is not deemed to control a VIE; however, once a trigger event occurs, the Company's control of the VIE typically increases. The Company continuously evaluates its power to direct the activities that most significantly impact the economic performance of VIEs that have debt obligations insured by the Company and, accordingly, where the Company is obligated to absorb VIE losses or receive benefits that could potentially be significant to the VIE. The Company obtains protective rights under its insurance contracts that give the Company additional controls over a VIE if there is either deterioration of deal performance or in the financial health of the deal servicer. The Company is deemed to be the control party for certain VIEs under GAAP, typically when its protective rights give it the power to both terminate and replace the deal servicer, which are characteristics specific to the Company's financial guaranty contracts. If the protective rights that could make the Company the control party have not been triggered, then the VIE is not consolidated. If the Company is deemed no longer to have those protective rights, the transaction is deconsolidated.

Outstanding_Exposure_Tables

Outstanding Exposure (Tables)	3 Months Ended
	Mar. 31, 2015
Schedule of Insured Financial Obligations [Line Items]
Debt Service Outstanding	The Company excludes amounts attributable to loss mitigation securities (unless otherwise indicated) from par and Debt Service outstanding, because it manages such securities as investments and not insurance exposure.
	Financial Guaranty
	Debt Service Outstanding
		Gross Debt Service							Net Debt Service
		Outstanding							Outstanding
		March 31,			December 31,				March 31,				December 31,
		2015			2014				2015				2014
		(in millions)
	Public finance	$	565,386		$	587,245			$	533,359			$	553,612
	Structured finance	54,546			59,477				51,300				56,010
	Total financial guaranty	$	619,932		$	646,722			$	584,659			$	609,622
Financial Guaranty Portfolio by Internal Rating	Financial Guaranty Portfolio by Internal Rating
	As of March 31, 2015
			Public Finance						Public Finance							Structured Finance							Structured Finance							Total
			U.S.						Non-U.S.							U.S							Non-U.S
	Rating		Net Par			%			Net Par				%			Net Par				%			Net Par				%			Net Par			%
	Category		Outstanding						Outstanding							Outstanding							Outstanding							Outstanding
			(dollars in millions)
	AAA		$	3,563		1.1	%		$	613			2.1	%		$	18,176			47.3	%		$	4,397			57.8	%		$	26,749		6.9	%
	AA		86,521			27.6			2,650				9			8,360				21.7			377				5			97,908			25.2
	A		171,308			54.7			7,091				23.9			2,228				5.8			365				4.7			180,992			46.4
	BBB		44,110			14.1			17,891				60.4			1,843				4.8			1,746				23			65,590			16.9
	BIG		7,942			2.5			1,374				4.6			7,823				20.4			721				9.5			17,860			4.6
	Total net par outstanding (1)		$	313,444		100	%		$	29,619			100	%		$	38,430			100	%		$	7,606			100	%		$	389,099		100	%
	_____________________
	-1	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of March 31, 2015, which are primarily in the BIG category.
	Financial Guaranty Portfolio by Internal Rating
	As of December 31, 2014
			Public Finance						Public Finance							Structured Finance							Structured Finance							Total
			U.S.						Non-U.S.							U.S							Non-U.S
	Rating		Net Par			%			Net Par				%			Net Par				%			Net Par				%			Net Par			%
	Category		Outstanding						Outstanding							Outstanding							Outstanding							Outstanding
			(dollars in millions)
	AAA		$	4,082		1.3	%		$	615			2	%		$	20,037			48.7	%		$	5,409			59.6	%		$	30,143		7.5	%
	AA		90,464			28.1			2,785				8.9			8,213				19.9			503				5.5			101,965			25.3
	A		176,298			54.7			7,192				22.9			2,940				7.1			445				4.9			186,875			46.3
	BBB		43,429			13.5			19,363				61.7			1,795				4.4			1,912				21.1			66,499			16.4
	BIG		7,850			2.4			1,404				4.5			8,186				19.9			807				8.9			18,247			4.5
	Total net par outstanding (1)		$	322,123		100	%		$	31,359			100	%		$	41,171			100	%		$	9,076			100	%		$	403,729		100	%
	_____________________
	-1	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of December 31, 2014, which are primarily in the BIG category.
Components of BIG Net Par Outstanding (Insurance and Credit Derivative Form)	Components of BIG Net Par Outstanding
	(Insurance and Credit Derivative Form)
	As of March 31, 2015
		BIG Net Par Outstanding															Net Par
		BIG 1			BIG 2				BIG 3				Total BIG				Outstanding
									(in millions)
	U.S. public finance	$	6,669		$	1,156			$	117			$	7,942			$	313,444
	Non-U.S. public finance	863			511				—				1,374				29,619
	First lien U.S. residential mortgage-backed securities ("RMBS"):
	Prime first lien	49			59				241				349				454
	Alt-A first lien	579			436				763				1,778				2,449
	Option ARM	9			53				108				170				374
	Subprime	179			529				831				1,539				3,935
	Second lien U.S. RMBS:
	Closed-end second lien	—			19				113				132				212
	Home equity lines of credit (“HELOCs”)	1,235			29				240				1,504				1,654
	Total U.S. RMBS	2,051			1,125				2,296				5,472				9,078
	Triple-X life insurance transactions	—			—				598				598				3,133
	Trust preferred securities (“TruPS”)	828			—				327				1,155				4,075
	Other structured finance	927			237				155				1,319				29,750
	Total	$	11,338		$	3,029			$	3,493			$	17,860			$	389,099
	Components of BIG Net Par Outstanding
	(Insurance and Credit Derivative Form)
	As of December 31, 2014
		BIG Net Par Outstanding															Net Par
		BIG 1			BIG 2				BIG 3				Total BIG				Outstanding
									(in millions)
	U.S. public finance	$	6,577		$	1,156			$	117			$	7,850			$	322,123
	Non-U.S. public finance	1,402			2				—				1,404				31,359
	First lien U.S. RMBS:
	Prime first lien	68			33				252				353				471
	Alt-A first lien	585			531				725				1,841				2,532
	Option ARM	47			18				118				183				407
	Subprime	156			654				765				1,575				4,051
	Second lien U.S. RMBS:
	Closed-end second lien	—			19				115				134				218
	HELOCs	1,012			36				509				1,557				1,738
	Total U.S. RMBS	1,868			1,291				2,484				5,643				9,417
	Triple-X life insurance transactions	—			—				598				598				3,133
	TruPS	997			—				336				1,333				4,326
	Other structured finance	1,021			240				158				1,419				33,371
	Total	$	11,865		$	2,689			$	3,693			$	18,247			$	403,729
BIG Net Par Outstanding and Number of Risks	BIG Net Par Outstanding
	and Number of Risks
	As of March 31, 2015
			Net Par Outstanding											Number of Risks(2)
	Description		Financial			Credit				Total				Financial			Credit			Total
			Guaranty			Derivative								Guaranty			Derivative
			Insurance(1)											Insurance(1)
			(dollars in millions)
	BIG:
	Category 1		$	9,887		$	1,451			$	11,338			164			18			182
	Category 2		2,345			684				3,029				73			12			85
	Category 3		2,705			788				3,493				119			25			144
	Total BIG		$	14,937		$	2,923			$	17,860			356			55			411
	BIG Net Par Outstanding
	and Number of Risks
	As of December 31, 2014
			Net Par Outstanding											Number of Risks(2)
	Description		Financial			Credit				Total				Financial			Credit			Total
			Guaranty			Derivative								Guaranty			Derivative
			Insurance(1)											Insurance(1)
			(dollars in millions)
	BIG:
	Category 1		$	10,195		$	1,670			$	11,865			164			18			182
	Category 2		2,135			554				2,689				75			14			89
	Category 3		2,892			801				3,693				119			24			143
	Total BIG		$	15,222		$	3,025			$	18,247			358			56			414
	_____________________
	(1)    Includes net par outstanding for FG VIEs.
	-2	A risk represents the aggregate of the financial guaranty policies that share the same revenue source for purposes of making Debt Service payments.
	The following table provides information on financial guaranty insurance contracts categorized as BIG.
	Financial Guaranty Insurance
	BIG Transaction Loss Summary
	As of March 31, 2015
		BIG  Categories
		BIG 1							BIG 2								BIG 3								Total				Effect of			Total
																									BIG, Net				Consolidating
		Gross			Ceded				Gross				Ceded				Gross				Ceded								FG VIEs
		(dollars in millions)
	Number of risks(1)	164			(61		)		73				(15		)		119				(38		)		356				—			356
	Remaining weighted-average contract period (in years)	9.8			7.2				8.7				7.2				9.9				7.3				10.1				—			10.1
	Outstanding exposure:
	Principal	$	11,993		$	(2,106	)		$	2,701			$	(356	)		$	2,847			$	(142	)		$	14,937			$	—		$	14,937
	Interest	6,082			(792		)		1,262				(127		)		1,013				(45		)		7,393				—			7,393
	Total(2)	$	18,075		$	(2,898	)		$	3,963			$	(483	)		$	3,860			$	(187	)		$	22,330			$	—		$	22,330
	Expected cash outflows (inflows)	$	1,655		$	(616	)		$	759			$	(84	)		$	1,721			$	(91	)		$	3,344			$	(343	)	$	3,001
	Potential recoveries
	Undiscounted R&W	(1		)	(1		)		(47		)		2				(133		)		7				(173		)		8			(165		)
	Other(3)	(1,583		)	600				(271		)		18				(449		)		47				(1,638		)		180			(1,458		)
	Total potential recoveries	(1,584		)	599				(318		)		20				(582		)		54				(1,811		)		188			(1,623		)
	Subtotal	71			(17		)		441				(64		)		1,139				(37		)		1,533				(155		)	1,378
	Discount	(7		)	0				(96		)		10				(336		)		7				(422		)		33			(389		)
	Present value of expected cash flows	$	64		$	(17	)		$	345			$	(54	)		$	803			$	(30	)		$	1,111			$	(122	)	$	989
	Deferred premium revenue	$	402		$	(75	)		$	104			$	(6	)		$	268			$	(25	)		$	668			$	(111	)	$	557
	Reserves (salvage)(4)	$	(10	)	$	(7	)		$	269			$	(52	)		$	468			$	(10	)		$	658			$	(77	)	$	581
	Financial Guaranty Insurance
	BIG Transaction Loss Summary
	As of December 31, 2014
		BIG Categories
		BIG 1							BIG 2								BIG 3								Total				Effect of			Total
																									BIG, Net				Consolidating
		Gross			Ceded				Gross				Ceded				Gross				Ceded								FG VIEs
		(dollars in millions)
	Number of risks(1)	164			(59		)		75				(15		)		119				(38		)		358				—			358
	Remaining weighted-average contract period (in years)	9.9			7.4				10.1				8.9				9.6				6.9				10.3				—			10.3
Outstanding exposure:
Principal	$	12,358		$	(2,163	)		$	2,421			$	(286	)		$	3,067			$	(175	)		$	15,222			$	—		$	15,222
Interest	6,350			(838		)		1,274				(121		)		1,034				(48		)		7,651				—			7,651
Total(2)	$	18,708		$	(3,001	)		$	3,695			$	(407	)		$	4,101			$	(223	)		$	22,873			$	—		$	22,873
Expected cash outflows (inflows)	$	1,762		$	(626	)		$	763			$	(77	)		$	1,716			$	(75	)		$	3,463			$	(345	)	$	3,118
Potential recoveries
Undiscounted R&W	(39		)	0				(48		)		2				(171		)		9				(247		)		8			(239		)
Other(3)	(1,687		)	608				(206		)		5				(404		)		30				(1,654		)		177			(1,477		)
Total potential recoveries	(1,726		)	608				(254		)		7				(575		)		39				(1,901		)		185			(1,716		)
Subtotal	36			(18		)		509				(70		)		1,141				(36		)		1,562				(160		)	1,402
Discount	3			0				(117		)		11				(353		)		9				(447		)		34			(413		)
Present value of expected cash flows	$	39		$	(18	)		$	392			$	(59	)		$	788			$	(27	)		$	1,115			$	(126	)	$	989
Deferred premium revenue	$	378		$	(70	)		$	119			$	(6	)		$	312			$	(33	)		$	700			$	(116	)	$	584
Reserves (salvage)(4)	$	(42	)	$	(5	)		$	278			$	(53	)		$	482			$	(10	)		$	650			$	(79	)	$	571
____________________
-1	A risk represents the aggregate of the financial guaranty policies that share the same revenue source for purposes of making Debt Service payments. The ceded number of risks represents the number of risks for which the Company ceded a portion of its exposure.
-2	Includes BIG amounts related to FG VIEs.
-3	Includes excess spread and draws on HELOCs.
-4	See table “Components of net reserves (salvage).”
Net Direct Economic Exposure to Selected European Countries	Net Direct Economic Exposure to Selected European Countries(1)
	As of March 31, 2015
		Hungary			Italy				Portugal				Spain				Total
		(in millions)
	Sovereign and sub-sovereign exposure:
	Non-infrastructure public finance (2)	$	—		$	779			$	91			$	211			$	1,081
	Infrastructure finance	265			11				11				120				407
	Total sovereign and sub-sovereign exposure	265			790				102				331				1,488
	Non-sovereign exposure:
	Regulated utilities	—			210				—				—				210
	RMBS	174			234				—				—				408
	Total non-sovereign exposure	174			444				—				—				618
	Total	$	439		$	1,234			$	102			$	331			$	2,106
	Total BIG (See Note 5)	$	370		$	—			$	102			$	331			$	803
	____________________
	-1	While the Company’s exposures are shown in U.S. dollars, the obligations the Company insures are in various currencies, primarily Euros. One of the residential mortgage-backed securities included in the table above includes residential mortgages in both Italy and Germany, and only the portion of the transaction equal to the portion of the original mortgage pool in Italian mortgages is shown in the table.
	-2	The exposure shown in the “Non-infrastructure public finance” category is from transactions backed by receivable payments from sub-sovereigns in Italy, Spain and Portugal. Sub-sovereign debt is debt issued by a governmental entity or government backed entity, or supported by such an entity, that is other than direct sovereign debt of the ultimate governing body of the country.
Puerto Rico [Member]
Schedule of Insured Financial Obligations [Line Items]
BIG Net Par Outstanding and Number of Risks	Amortization Schedule of Puerto Rico BIG Net Par Outstanding
	and BIG Net Debt Service Outstanding
	As of March 31, 2015
		Scheduled BIG Net Par Amortization											Scheduled BIG Net Debt Service Amortization
		Previously Subject to the Voided Recovery Act			Not Previously Subject to the Voided Recovery Act				Total				Previously Subject to the Voided Recovery Act				Not Previously Subject to the Voided Recovery Act				Total
		(in millions)
	2015 (April 1 - June 30)	$	0		$	0			$	0			$	2			$	1			$	3
	2015 (July 1 - September 30)	126			171				297				186				227				413
	2015 (October 1 - December 31)	0			33				33				2				35				37
	2016	84			183				267				200				287				487
	2017	41			166				207				153				262				415
	2018	48			109				157				158				195				353
	2019	61			126				187				168				207				375
	2020	73			182				255				176				258				434
	2021	51			58				109				151				123				274
	2022	43			67				110				140				129				269
	2023	102			39				141				198				99				297
	2024	82			78				160				173				136				309
	2025-2029	576			340				916				951				566				1,517
	2030-2034	440			387				827				696				542				1,238
	2035 -2039	397			272				669				525				304				829
	2040 -2044	78			12				90				146				13				159
	2045 -2047	246			—				246				272				—				272
	Total	$	2,448		$	2,223			$	4,671			$	4,297			$	3,384			$	7,681
Gross Par and Gross Debt Service Outstanding	Puerto Rico
	Gross Par and Gross Debt Service Outstanding
		Gross Par Outstanding							Gross Debt Service Outstanding
		March 31,			December 31,				March 31,				December 31,
		2015			2014				2015				2014
		(in millions)
	Previously Subject to the Voided Recovery Act (1)	$	3,059		$	3,058			$	5,252			$	5,326
	Not Previously Subject to the Voided Recovery Act	2,977			2,977				4,675				4,748
	Total	$	6,036		$	6,035			$	9,927			$	10,074
	____________________
	-1	On February 6, 2015, the U.S. District Court for the District of Puerto Rico ruled that the Recovery Act is preempted by the Federal Bankruptcy Code and is therefore void. On February 19, 2015, the Commonwealth appealed the ruling to the U.S. Court of Appeals for the First Circuit.
Schedule of Geographic Exposure of Net Par Outstanding	Puerto Rico
	Net Par Outstanding
			As of					As of
			31-Mar-15					31-Dec-14
			Total			Internal Rating		Total				Internal Rating
			(in millions)
	Exposures Previously Subject to the Voided Recovery Act:
	PRHTA (Transportation revenue)		$	844		BB-		$	844			BB-
	PREPA		773			B-		772				B-
	Puerto Rico Aqueduct and Sewer Authority		384			BB-		384				BB-
	PRHTA (Highway revenue)		273			BB		273				BB
	Puerto Rico Convention Center District Authority		174			BB-		174				BB-
	Total		2,448					2,447
	Exposures Not Previously Subject to the Voided Recovery Act:
	Commonwealth of Puerto Rico - General Obligation Bonds		1,672			BB		1,672				BB
	Puerto Rico Municipal Finance Agency		399			BB-		399				BB-
	Puerto Rico Sales Tax Financing Corporation		269			BBB		269				BBB
	Puerto Rico Public Buildings Authority		100			BB		100				BB
	GDB		33			BB		33				BB
	Puerto Rico Infrastructure Finance Authority		18			BB-		18				BB-
	University of Puerto Rico		1			BB-		1				BB-
	Total		2,492					2,492
	Total net exposure to Puerto Rico		$	4,940				$	4,939

Financial_Guaranty_Insurance_P1

Financial Guaranty Insurance Premiums (Tables)	3 Months Ended
	Mar. 31, 2015
Insurance [Abstract]
Net Earned Premiums	Net Earned Premiums
		First Quarter
		2015			2014
		(in millions)
	Scheduled net earned premiums	$	96		$	107
	Acceleration of net earned premiums	41			19
	Accretion of discount on net premiums receivable	4			6
	Financial guaranty insurance net earned premiums	141			132
	Other	1			—
	Net earned premiums(1)	$	142		$	132
	___________________
	-1	Excludes $5 million and $17 million for First Quarter 2015 and 2014, respectively, related to consolidated FG VIEs.
Components of Unearned Premium Reserve	Components of Unearned Premium Reserve
		As of March 31, 2015								As of December 31, 2014
		Gross			Ceded			Net(1)		Gross		Ceded			Net(1)
		(in millions)
	Deferred premium revenue:
	Financial guaranty insurance	$	4,038		$	370		$	3,668	$	4,167	$	387		$	3,780
	Other	1			—			1		0		—			0
	Deferred premium revenue	$	4,039		$	370		$	3,669	$	4,167	$	387		$	3,780
	Contra-paid (2)	88			(5		)	93		94		(6		)	100
	Unearned premium reserve	$	4,127		$	365		$	3,762	$	4,261	$	381		$	3,880
	____________________
	-1	Excludes $125 million and $125 million of deferred premium revenue, and $41 million and $42 million of contra-paid related to FG VIEs as of March 31, 2015 and December 31, 2014, respectively.
	-2	See Note 6, "Financial Guaranty Insurance Losses– Insurance Contracts' Loss Information" for an explanation of "contra-paid".
Gross Premium Receivable, Net of Commissions on Assumed Business Roll Forward	Gross Premium Receivable,
	Net of Commissions on Assumed Business
	Roll Forward
		First Quarter
		2015			2014
		(in millions)
	Beginning of period, December 31	$	729		$	876
	Gross premium written, net of commissions on assumed business	36			33
	Gross premiums received, net of commissions on assumed business	(36		)	(53		)
	Adjustments:
	Changes in the expected term	(6		)	(3		)
	Accretion of discount, net of commissions on assumed business	5			7
	Foreign exchange translation	(25		)	2
	Consolidation/deconsolidation of FG VIEs	(4		)	1
	Other adjustments	0			—
	End of period, March 31 (1)	$	699		$	863
	____________________
	-1	Excludes $22 million and $18 million as of March 31, 2015 and March 31, 2014, respectively, related to consolidated FG VIEs.
Expected Collections of Gross Premiums Receivable, Net of Ceding Commissions (Undiscounted)	Expected Collections of
	Financial Guaranty Gross Premiums Receivable,
	Net of Commissions on Assumed Business
	(Undiscounted)
		As of March 31, 2015
		(in millions)
	2015 (April 1 – June 30)	$	23
	2015 (July 1 – September 30)	24
	2015 (October 1 – December 31)	19
	2016	74
	2017	67
	2018	61
	2019	57
	2020-2024	238
	2025-2029	154
	2030-2034	108
	After 2034	98
	Total(1)	$	923
	____________________
	-1	Excludes expected cash collections on FG VIEs of $28 million.
Schedule of Net Earned Premiums	Scheduled Financial Guaranty Net Earned Premiums
		As of March 31, 2015
		(in millions)
	2015 (April 1 – June 30)	$	91
	2015 (July 1 – September 30)	89
	2015 (October 1 – December 31)	86
	2016	334
	2017	294
	2018	267
	2019	244
	2020-2024	955
	2025-2029	610
	2030-2034	373
	After 2034	325
	Net deferred premium revenue(1)	3,668
	Future accretion	198
	Total future net earned premiums	$	3,866
	____________________
	-1	Excludes scheduled net earned premiums on consolidated FG VIEs of $125 million.
Selected Information for Policies Paid in Installments	Selected Information for Financial Guaranty Policies Paid in Installments
		As of			As of
		31-Mar-15			31-Dec-14
		(dollars in millions)
	Premiums receivable, net of commission payable	$	699		$	729
	Gross deferred premium revenue	1,334			1,370
	Weighted-average risk-free rate used to discount premiums	3.4		%	3.5		%
	Weighted-average period of premiums receivable (in years)	9.4			9.4

Expected_Loss_to_be_Paid_Table

Expected Loss to be Paid (Tables)	3 Months Ended
	Mar. 31, 2015
Expected Losses [Abstract]
Net Expected Loss to be Paid After Net Expected Recoveries for Breaches of R&W Roll Forward	Net Expected Loss to be Paid
	After Net Expected Recoveries for Breaches of R&W
	Roll Forward by Sector
	First Quarter 2015
		Net Expected				Economic Loss				(Paid)			Net Expected
		Loss to be				Development				Recovered			Loss to be
		Paid (Recovered)								Losses (1)			Paid (Recovered)
		as of											as of
		December 31, 2014 (2)											March 31,2015 (2)
		(in millions)
	Public Finance:
	U.S. public finance	$	303			$	9			$	(2	)	$	310
	Non-U.S public finance	45				(3		)		—			42
	Public Finance	348				6				(2		)	352
	Structured Finance:
	U.S. RMBS:
	First lien:
	Prime first lien	4				0				(1		)	3
	Alt-A first lien	304				(5		)		(10		)	289
	Option ARM	(16		)		4				(4		)	(16		)
	Subprime	303				(1		)		(9		)	293
	Total first lien	595				(2		)		(24		)	569
	Second lien:
	Closed-end second lien	8				1				2			11
	HELOCs	(19		)		5				4			(10		)
	Total second lien	(11		)		6				6			1
	Total U.S. RMBS	584				4				(18		)	570
	Triple-X life insurance transactions	161				5				(1		)	165
	TruPS	23				(9		)		—			14
	Other structured finance	57				(8		)		3			52
	Structured Finance	825				(8		)		(16		)	801
	Subtotal	1,173				(2		)		(18		)	1,153
	Other insurance	(4		)		(1		)		6			1
	Total	$	1,169			$	(3	)		$	(12	)	$	1,154
	Net Expected Loss to be Paid
	After Net Expected Recoveries for Breaches of R&W
	Roll Forward by Sector
	First Quarter 2014
		Net Expected				Economic Loss				(Paid)			Net Expected
		Loss to be				Development				Recovered			Loss to be
		Paid (Recovered)								Losses (1)			Paid (Recovered)
		as of											as of
		31-Dec-13											March 31,2014
		(in millions)
	Public Finance:
	U.S. public finance	$	264			$	23			$	(6	)	$	281
	Non-U.S public finance	57				—				—			57
	Public Finance	321				23				(6		)	338
	Structured Finance:
	U.S. RMBS:
	First lien:
	Prime first lien	21				(3		)		—			18
	Alt-A first lien	304				8				(4		)	308
	Option ARM	(9		)		(15		)		(4		)	(28		)
	Subprime	304				(7		)		(2		)	295
	Total first lien	620				(17		)		(10		)	593
	Second lien:
	Closed-end second lien	(11		)		5				2			(4		)
	HELOCs	(116		)		2				5			(109		)
	Total second lien	(127		)		7				7			(113		)
	Total U.S. RMBS	493				(10		)		(3		)	480
	Triple-X life insurance transactions	75				13				(1		)	87
	TruPS	51				(19		)		—			32
	Other structured finance	45				6				—			51
Structured Finance	664				(10		)		(4		)	650
Subtotal	985				13				(10		)	988
Other insurance	(3		)		(1		)		—			(4		)
Total	$	982			$	12			$	(10	)	$	984
____________________
-1	Net of ceded paid losses, whether or not such amounts have been settled with reinsurers. Ceded paid losses are typically settled 45 days after the end of the reporting period. Such amounts are recorded in reinsurance recoverable on paid losses included in other assets. The Company paid $4 million and $6 million in loss adjustment expenses ("LAE") for First Quarter 2015 and 2014, respectively.
-2	Includes expected LAE to be paid of $13 million as of March 31, 2015 and $16 million as of December 31, 2014.
Net Expected Recoveries from Breaches of R&W Rollforward	Net Expected Recoveries from
	Breaches of R&W Rollforward
	First Quarter 2015
		Future Net				R&W Development				R&W (Recovered)			Future Net
		R&W Benefit as of				and Accretion of				During 2015			R&W Benefit as of
		December 31, 2014				Discount							March 31,2015 (1)
						During 2015
		(in millions)
	U.S. RMBS:
	First lien:
	Prime first lien	$	2			$	(1	)		$	—		$	1
	Alt-A first lien	106				(10		)		(2		)	94
	Option ARM	15				(20		)		(15		)	(20		)
	Subprime	109				(19		)		(3		)	87
	Total first lien	232				(50		)		(20		)	162
	Second lien:
	Closed-end second lien	85				(1		)		(1		)	83
	HELOC	—				—				—			—
	Total second lien	85				(1		)		(1		)	83
	Total	$	317			$	(51	)		$	(21	)	$	245
	Net Expected Recoveries from
	Breaches of R&W Rollforward
	First Quarter 2014
		Future Net				R&W Development				R&W (Recovered)			Future Net
		R&W Benefit as of				and Accretion of				During 2014			R&W Benefit as of
		December 31, 2013				Discount							March 31, 2014
						During 2014
		(in millions)
	U.S. RMBS:
	First lien:
	Prime first lien	$	4			$	(1	)		$	—		$	3
	Alt-A first lien	274				3				(8		)	269
	Option ARM	173				9				(30		)	152
	Subprime	118				28				—			146
	Total first lien	569				39				(38		)	570
	Second lien:
	Closed-end second lien	98				(3		)		—			95
	HELOC	45				12				(1		)	56
	Total second lien	143				9				(1		)	151
	Total	$	712			$	48			$	(39	)	$	721
	___________________
	(1)    See the section "Breaches of Representations and Warranties" below for eligible assets held in trust.
Net Expected Loss to be Paid By Accounting Model	Net Expected Loss to be Paid (Recovered)
	By Accounting Model
	As of March 31, 2015
		Financial				FG VIEs(1)				Credit			Total
		Guaranty								Derivatives(2)
		Insurance
		(in millions)
	Public Finance:
	U.S. public finance	$	310			$	—			$	—		$	310
	Non-U.S. public finance	42				—				—			42
	Public Finance	352				—				—			352
	Structured Finance:
	U.S. RMBS:
	First lien:
	Prime first lien	3				—				—			3
	Alt-A first lien	278				17				(6		)	289
	Option ARM	(17		)		—				1			(16		)
	Subprime	157				69				67			293
	Total first lien	421				86				62			569
	Second lien:
	Closed-end second lien	(24		)		31				4			11
	HELOCs	(15		)		5				—			(10		)
	Total second lien	(39		)		36				4			1
	Total U.S. RMBS	382				122				66			570
	Triple-X life insurance transactions	157				—				8			165
	TruPS	0				—				14			14
	Other structured finance	98				—				(46		)	52
	Structured Finance	637				122				42			801
	Subtotal	$	989			$	122			$	42		$	1,153
	Other												1
	Total												$	1,154
	Net Expected Loss to be Paid (Recovered)
	By Accounting Model
	As of December 31, 2014
		Financial				FG VIEs(1)				Credit			Total
		Guaranty								Derivatives(2)
		Insurance
		(in millions)
	Public Finance:
	U.S. public finance	$	303			$	—			$	—		$	303
	Non-U.S. public finance	45				—				—			45
	Public Finance	348				—				—			348
	Structured Finance:
	U.S. RMBS:
	First lien:
	Prime first lien	2				—				2			4
	Alt-A first lien	288				17				(1		)	304
	Option ARM	(15		)		—				(1		)	(16		)
	Subprime	163				71				69			303
	Total first lien	438				88				69			595
	Second lien:
	Closed-end second lien	(27		)		31				4			8
	HELOCs	(26		)		7				—			(19		)
	Total second lien	(53		)		38				4			(11		)
	Total U.S. RMBS	385				126				73			584
	Triple-X life insurance transactions	153				—				8			161
	TruPS	1				—				22			23
	Other structured finance	102				—				(45		)	57
	Structured Finance	641				126				58			825
	Subtotal	$	989			$	126			$	58		1,173
	Other												(4		)
	Total												$	1,169
	___________________
	(1)    Refer to Note 9, Consolidated Variable Interest Entities.
(2)    Refer to Note 8, Financial Guaranty Contracts Accounted for as Credit Derivatives.
Schedule of Net Economic Loss Development	Net Economic Loss Development (Benefit)
	By Accounting Model
	First Quarter 2015
		Financial				FG VIEs(1)				Credit			Total
		Guaranty								Derivatives(2)
		Insurance
		(in millions)
	Public Finance:
	U.S. public finance	$	9			$	—			$	—		$	9
	Non-U.S. public finance	(3		)		—				—			(3		)
	Public Finance	6				—				—			6
	Structured Finance:
	U.S. RMBS:
	First lien:
	Prime first lien	1				—				(1		)	0
	Alt-A first lien	2				—				(7		)	(5		)
	Option ARM	1				—				3			4
	Subprime	(4		)		4				(1		)	(1		)
	Total first lien	0				4				(6		)	(2		)
	Second lien:
	Closed-end second lien	1				1				(1		)	1
	HELOCs	7				(2		)		—			5
	Total second lien	8				(1		)		(1		)	6
	Total U.S. RMBS	8				3				(7		)	4
	Triple-X life insurance transactions	4				—				1			5
	TruPS	(1		)		—				(8		)	(9		)
	Other structured finance	(5		)		—				(3		)	(8		)
	Structured Finance	6				3				(17		)	(8		)
	Subtotal	$	12			$	3			$	(17	)	$	(2	)
	Other												(1		)
	Total												$	(3	)
	Net Economic Loss Development (Benefit)
	By Accounting Model
	First Quarter 2014
		Financial				FG VIEs(1)				Credit			Total
		Guaranty								Derivatives(2)
		Insurance
		(in millions)
	Public Finance:
	U.S. public finance	$	23			$	—			$	—		$	23
	Non-U.S. public finance	—				—				—			—
	Public Finance	23				—				—			23
	Structured Finance:
	U.S. RMBS:
	First lien:
	Prime first lien	—				—				(3		)	(3		)
	Alt-A first lien	19				(12		)		1			8
	Option ARM	(16		)		1				—			(15		)
	Subprime	(8		)		(2		)		3			(7		)
	Total first lien	(5		)		(13		)		1			(17		)
	Second lien:
	Closed-end second lien	(1		)		2				4			5
	HELOCs	(56		)		58				—			2
	Total second lien	(57		)		60				4			7
	Total U.S. RMBS	(62		)		47				5			(10		)
	Triple-X life insurance transactions	13				—				—			13
	TruPS	(1		)		—				(18		)	(19		)
	Other structured finance	4				—				2			6
	Structured Finance	(46		)		47				(11		)	(10		)
	Subtotal	$	(23	)		$	47			$	(11	)	13
	Other												(1		)
	Total												$	12
	_________________
	(1)    Refer to Note 9, Consolidated Variable Interest Entities.
(2)    Refer to Note 8, Financial Guaranty Contracts Accounted for as Credit Derivatives.
Liquidation Rates and Key Assumptions in Base Case Expected Loss Estimates First Lien RMBS	First Lien Liquidation Rates
		March 31, 2015		December 31, 2014
	Current Loans Modified in the Previous 12 Months
	Alt A and Prime	25%		25%
	Option ARM	25		25
	Subprime	25		25
	Current Loans Delinquent in the Previous 12 Months
	Alt A and Prime	25		25
	Option ARM	25		25
	Subprime	25		25
	30 – 59 Days Delinquent
	Alt A and Prime	35		35
	Option ARM	40		40
	Subprime	35		35
	60 – 89 Days Delinquent
	Alt A and Prime	50		50
	Option ARM	55		55
	Subprime	40		40
	90+ Days Delinquent
	Alt A and Prime	60		60
	Option ARM	65		65
	Subprime	55		55
	Bankruptcy
	Alt A and Prime	45		45
	Option ARM	50		50
	Subprime	40		40
	Foreclosure
	Alt A and Prime	75		75
	Option ARM	80		80
	Subprime	70		70
	Real Estate Owned
	All	100		100
	Key Assumptions in Base Case Expected Loss Estimates
	First Lien RMBS(1)
		As of							As of
		31-Mar-15							31-Dec-14
		Range					Weighted Average		Range				Weighted Average
	Alt-A First Lien
	Plateau CDR	2.6	%	–	13.10%		7.40%		2	%	–	13.40%	7.30%
	Intermediate CDR	0.5	%	–	2.60%		1.50%		0.4	%	–	2.70%	1.50%
	Period until intermediate CDR	48 months							48 months
	Final CDR	0.1	%	–	0.70%		0.30%		0.1	%	–	0.70%	0.30%
	Initial loss severity:
	2005 and prior	60.00%							60.00%
	2006	70.00%							70.00%
	2007	65.00%							65.00%
	Initial conditional prepayment rate ("CPR")	2.7	%	–	22.40%		8.10%		1.7	%	–	21.00%	7.70%
	Final CPR(2)	15	%	–	22.40%		15.20%		15%
	Option ARM
	Plateau CDR	4.5	%	–	12.90%		9.90%		4.3	%	–	14.20%	10.60%
	Intermediate CDR	0.9	%	–	2.60%		2.00%		0.9	%	–	2.80%	2.10%
	Period until intermediate CDR	48 months							48 months
	Final CDR	0.2	%	–	0.60%		0.50%		0.2	%	–	0.70%	0.50%
	Initial loss severity:
	2005 and prior	60.00%							60.00%
	2006	70.00%							70.00%
	2007	65.00%							65.00%
	Initial CPR	1.8	%	–	12.70%		4.90%		1.1	%	–	11.80%	4.90%
	Final CPR(2)	15%							15%
	Subprime
	Plateau CDR	4.8	%	–	14.40%		10.20%		4.9	%	–	15.00%	10.60%
	Intermediate CDR	1	%	–	2.90%		2.00%		1	%	–	3.00%	2.10%
	Period until intermediate CDR	48 months							48 months
	Final CDR	0.2	%	–	0.70%		0.40%		0.2	%	–	0.70%	0.40%
Initial loss severity:
2005 and prior	75.00%							75.00%
2006	90.00%							90.00%
2007	90.00%							90.00%
Initial CPR	0	%	–	9.70%		4.70%		0	%	–	10.50%	6.10%
Final CPR(2)	15%							15%
____________________
(1)                                Represents variables for most heavily weighted scenario (the “base case”).
(2)	For transactions where the initial CPR is higher than the final CPR, the initial CPR is held constant and the final CPR is not used.
Key Assumptions in Base Case Expected Loss Estimates Second Lien RMBS	Key Assumptions in Base Case Expected Loss Estimates
	Second Lien RMBS(1)
	HELOC key assumptions	As of							As of
		31-Mar-15							31-Dec-14
		Range					Weighted Average		Range				Weighted Average
	Plateau CDR	2.3	%	–	7.50%		4.40%		2.8	%	–	6.80%	4.10%
	Final CDR trended down to	0.5	%	–	3.20%		1.20%		0.5	%	–	3.20%	1.20%
	Period until final CDR	34 months							34 months
	Initial CPR	6.9	%	–	23.20%		10.20%		6.9	%	–	21.80%	11.00%
	Final CPR(2)	10	%	–	23.20%		15.20%		15	%	–	21.80%	15.50%
	Loss severity	90	%	–	98.00%		90.40%		90	%	–	98.00%	90.40%
	Closed-end second lien key assumptions	As of							As of
		31-Mar-15							31-Dec-14
		Range					Weighted Average		Range				Weighted Average
	Plateau CDR	4.7	%	–	12.40%		6.90%		5.5	%	–	12.50%	7.20%
	Final CDR trended down to	3.5	%	–	9.10%		4.90%		3.5	%	–	9.10%	4.90%
	Period until final CDR	34 months							34 months
	Initial CPR	3.4	%	–	11.80%		7.60%		2.8	%	–	13.90%	9.90%
	Final CPR(2)	15%							15%
	Loss severity	98%							98%
	____________________
	-1	Represents variables for most heavily weighted scenario (the “base case”).
	(2)	For transactions where the initial CPR is higher than the final CPR, the initial CPR is held constant and the final CPR is not used.
Components of Development and Accretion Amounts of Estimated Recoveries	The following table provides a breakdown of the development and accretion amount in the roll forward of estimated recoveries associated with claims for breaches of R&W.
	Components of R&W Development
		First Quarter
		2015				2014
		(in millions)
	Estimated increase (decrease) in defaults that will result in additional (lower) breaches(1)	$	(52	)		$	0
	Inclusion or removal of deals with breaches of R&W during period	0				—
	Change in recovery assumptions	—				10
	Settlements and anticipated settlements	—				35
	Accretion of discount on balance	1				3
	Total	$	(51	)		$	48
	____________________
	-1	The negative R&W development is offset by higher anticipated cash flows in the covered transactions that were related to a third party settlement.

Financial_Guaranty_Insurance_L1

Financial Guaranty Insurance Losses (Tables)	3 Months Ended
	Mar. 31, 2015
Insurance [Abstract]
Loss and LAE Reserve and Salvage and Subrogation Recoverable Net of Reinsurance Insurance Contracts	Loss and LAE Reserve and Salvage and Subrogation Recoverable
	Net of Reinsurance
	Insurance Contracts
		As of March 31, 2015									As of December 31, 2014
		Loss and			Salvage and			Net Reserve (Recoverable)			Loss and			Salvage and				Net Reserve (Recoverable)
		LAE			Subrogation						LAE			Subrogation
		Reserve, net			Recoverable, net						Reserve, net			Recoverable, net
		(in millions)
	Public Finance:
	U.S. public finance	$	253		$	8		$	245		$	243		$	8			$	235
	Non-U.S. public finance	28			—			28			30			—				30
	Public Finance	281			8			273			273			8				265
	Structured Finance:
	U.S. RMBS:
	First lien:
	Prime first lien	2			—			2			2			—				2
	Alt-A first lien	80			—			80			87			—				87
	Option ARM	24			42			(18		)	28			40				(12		)
	Subprime	159			6			153			166			8				158
	First lien	265			48			217			283			48				235
	Second lien:
	Closed-end second lien	5			37			(32		)	4			39				(35		)
	HELOCs	2			29			(27		)	3			39				(36		)
	Second lien	7			66			(59		)	7			78				(71		)
	Total U.S. RMBS	272			114			158			290			126				164
	Triple-X life insurance transactions	144			—			144			140			—				140
	TruPS	—			—			—			0			—				0
	Other structured finance	90			—			90			96			2				94
	Structured Finance	506			114			392			526			128				398
	Financial guaranty	787			122			665			799			136				663
	Other recoverables	—			7			(7		)	—			13				(13		)
	Subtotal	787			129			658			799			149				650
	Effect of consolidating FG VIEs	(78		)	(1		)	(77		)	(80		)	(1		)		(79		)
	Subtotal	709			128			581			719			148				571
	Other	1			—			1			2			6				(4		)
	Total (1)	$	710		$	128		$	582		$	721		$	154			$	567
	____________________
	-1	See “Components of Net Reserves (Salvage)” table for loss and LAE reserve and salvage and subrogation recoverable components.
Components of Net Reserves (Salvage) Insurance Contracts	Components of Net Reserves (Salvage)
	Insurance Contracts
		As of			As of
		31-Mar-15			31-Dec-14
		(in millions)
	Loss and LAE reserve	$	787		$	799
	Reinsurance recoverable on unpaid losses	(77		)	(78		)
	Loss and LAE reserve, net	710			721
	Salvage and subrogation recoverable	(128		)	(151		)
	Salvage and subrogation payable(1)	7			10
	Other recoverables	(7		)	(13		)
	Salvage and subrogation recoverable, net and other recoverable	(128		)	(154		)
	Subtotal	582			567
	Less: other (non-financial guaranty business)	1			(4		)
	Net reserves (salvage) - financial guaranty	$	581		$	571
	____________________
	-1	Recorded as a component of reinsurance balances payable.
Balance Sheet Classification of Net Expected Recoveries for Breaches of R&W Insurance Contracts	Balance Sheet Classification of
	Net Expected Recoveries for Breaches of R&W
	Insurance Contracts
		As of March 31, 2015									As of December 31, 2014
		For all			Effect of			Reported on			For all			Effect of				Reported on
		Financial			Consolidating			Balance Sheet(1)			Financial			Consolidating				Balance Sheet(1)
		Guaranty			FG VIEs						Guaranty			FG VIEs
		Insurance									Insurance
		Contracts									Contracts
		(in millions)
	Salvage and subrogation recoverable, net	$	2		$	—		$	2		$	20		$	—			$	20
	Loss and LAE reserve, net	146			(8		)	138			185			(8		)		177
	____________________
	-1	The remaining benefit for R&W is either recorded at fair value in FG VIE assets, or not recorded on the balance sheet until the total loss, net of R&W, exceeds unearned premium reserve.
Reconciliation of Net Expected Loss to be Paid and Net Expected Loss to be Expensed Financial Guaranty Insurance Contracts	Reconciliation of Net Expected Loss to be Paid and
	Net Expected Loss to be Expensed
	Financial Guaranty Insurance Contracts
		As of
		31-Mar-15
		(in millions)
	Net expected loss to be paid	$	1,111
	Less: net expected loss to be paid for FG VIEs	122
	Total	989
	Contra-paid, net	(93		)
	Salvage and subrogation recoverable, net of reinsurance	121
	Loss and LAE reserve, net of reinsurance	(709		)
	Other recoveries	7
	Net expected loss to be expensed (present value) (1)	$	315
	____________________
	-1	Excludes $86 million as of March 31, 2015, related to consolidated FG VIEs.
Net Expected Loss to be Expensed Insurance Contracts	Net Expected Loss to be Expensed
	Financial Guaranty Insurance Contracts
		As of
		31-Mar-15
		(in millions)
	2015 (April 1 – June 30)	$	7
	2015 (July 1 – September 30)	9
	2015 (October 1 – December 31)	11
	Subtotal 2015	27
	2016	36
	2017	27
	2018	25
	2019	23
	2020-2024	77
	2025-2029	45
	2030-2034	34
	After 2034	21
	Net expected loss to be expensed	315
	Discount	389
	Total expected future loss and LAE	$	704
Loss and LAE Reported on the Consolidated Statements of Operations	Loss and LAE
	Reported on the
	Consolidated Statements of Operations
		First Quarter
		2015			2014
		(in millions)
	Public Finance:
	U.S. public finance	$	13		$	26
	Non-U.S. public finance	5			1
	Public finance	18			27
	Structured Finance:
	U.S. RMBS:
	First lien:
	Prime first lien	0			0
	Alt-A first lien	(2		)	7
	Option ARM	(1		)	(8		)
	Subprime	0			(8		)
	First lien	(3		)	(9		)
	Second lien:
	Closed-end second lien	1			—
	HELOCs	9			8
	Second lien	10			8
	Total U.S. RMBS	7			(1		)
	Triple-X life insurance transactions	6			13
	TruPS	(1		)	(1		)
	Other structured finance	(6		)	3
	Structured finance	6			14
	Subtotal	24			41
	Other	(1		)	(1		)
	Loss and LAE on insurance contracts before FG VIE consolidation	23			40
	Effect of consolidating FG VIEs	(5		)	1
	Loss and LAE	$	18		$	41
Financial Guaranty Insurance BIG Transaction Loss Summary	BIG Net Par Outstanding
	and Number of Risks
	As of March 31, 2015
			Net Par Outstanding									Number of Risks(2)
	Description		Financial			Credit			Total			Financial		Credit			Total
			Guaranty			Derivative						Guaranty		Derivative
			Insurance(1)									Insurance(1)
			(dollars in millions)
	BIG:
	Category 1		$	9,887		$	1,451		$	11,338		164		18			182
	Category 2		2,345			684			3,029			73		12			85
	Category 3		2,705			788			3,493			119		25			144
	Total BIG		$	14,937		$	2,923		$	17,860		356		55			411
	BIG Net Par Outstanding
	and Number of Risks
	As of December 31, 2014
			Net Par Outstanding									Number of Risks(2)
	Description		Financial			Credit			Total			Financial		Credit			Total
			Guaranty			Derivative						Guaranty		Derivative
			Insurance(1)									Insurance(1)
			(dollars in millions)
	BIG:
	Category 1		$	10,195		$	1,670		$	11,865		164		18			182
	Category 2		2,135			554			2,689			75		14			89
	Category 3		2,892			801			3,693			119		24			143
	Total BIG		$	15,222		$	3,025		$	18,247		358		56			414
	_____________________
	(1)    Includes net par outstanding for FG VIEs.
	-2	A risk represents the aggregate of the financial guaranty policies that share the same revenue source for purposes of making Debt Service payments.
	The following table provides information on financial guaranty insurance contracts categorized as BIG.
	Financial Guaranty Insurance
	BIG Transaction Loss Summary
	As of March 31, 2015
		BIG  Categories
		BIG 1						BIG 2						BIG 3							Total			Effect of			Total
																					BIG, Net			Consolidating
		Gross			Ceded			Gross			Ceded			Gross				Ceded						FG VIEs
		(dollars in millions)
	Number of risks(1)	164			(61		)	73			(15		)	119				(38		)	356			—			356
	Remaining weighted-average contract period (in years)	9.8			7.2			8.7			7.2			9.9				7.3			10.1			—			10.1
	Outstanding exposure:
	Principal	$	11,993		$	(2,106	)	$	2,701		$	(356	)	$	2,847			$	(142	)	$	14,937		$	—		$	14,937
	Interest	6,082			(792		)	1,262			(127		)	1,013				(45		)	7,393			—			7,393
	Total(2)	$	18,075		$	(2,898	)	$	3,963		$	(483	)	$	3,860			$	(187	)	$	22,330		$	—		$	22,330
	Expected cash outflows (inflows)	$	1,655		$	(616	)	$	759		$	(84	)	$	1,721			$	(91	)	$	3,344		$	(343	)	$	3,001
	Potential recoveries
	Undiscounted R&W	(1		)	(1		)	(47		)	2			(133		)		7			(173		)	8			(165		)
	Other(3)	(1,583		)	600			(271		)	18			(449		)		47			(1,638		)	180			(1,458		)
	Total potential recoveries	(1,584		)	599			(318		)	20			(582		)		54			(1,811		)	188			(1,623		)
	Subtotal	71			(17		)	441			(64		)	1,139				(37		)	1,533			(155		)	1,378
	Discount	(7		)	0			(96		)	10			(336		)		7			(422		)	33			(389		)
	Present value of expected cash flows	$	64		$	(17	)	$	345		$	(54	)	$	803			$	(30	)	$	1,111		$	(122	)	$	989
	Deferred premium revenue	$	402		$	(75	)	$	104		$	(6	)	$	268			$	(25	)	$	668		$	(111	)	$	557
	Reserves (salvage)(4)	$	(10	)	$	(7	)	$	269		$	(52	)	$	468			$	(10	)	$	658		$	(77	)	$	581
	Financial Guaranty Insurance
	BIG Transaction Loss Summary
	As of December 31, 2014
		BIG Categories
		BIG 1						BIG 2						BIG 3							Total			Effect of			Total
																					BIG, Net			Consolidating
		Gross			Ceded			Gross			Ceded			Gross				Ceded						FG VIEs
		(dollars in millions)
	Number of risks(1)	164			(59		)	75			(15		)	119				(38		)	358			—			358
	Remaining weighted-average contract period (in years)	9.9			7.4			10.1			8.9			9.6				6.9			10.3			—			10.3
Outstanding exposure:
Principal	$	12,358		$	(2,163	)	$	2,421		$	(286	)	$	3,067			$	(175	)	$	15,222		$	—		$	15,222
Interest	6,350			(838		)	1,274			(121		)	1,034				(48		)	7,651			—			7,651
Total(2)	$	18,708		$	(3,001	)	$	3,695		$	(407	)	$	4,101			$	(223	)	$	22,873		$	—		$	22,873
Expected cash outflows (inflows)	$	1,762		$	(626	)	$	763		$	(77	)	$	1,716			$	(75	)	$	3,463		$	(345	)	$	3,118
Potential recoveries
Undiscounted R&W	(39		)	0			(48		)	2			(171		)		9			(247		)	8			(239		)
Other(3)	(1,687		)	608			(206		)	5			(404		)		30			(1,654		)	177			(1,477		)
Total potential recoveries	(1,726		)	608			(254		)	7			(575		)		39			(1,901		)	185			(1,716		)
Subtotal	36			(18		)	509			(70		)	1,141				(36		)	1,562			(160		)	1,402
Discount	3			0			(117		)	11			(353		)		9			(447		)	34			(413		)
Present value of expected cash flows	$	39		$	(18	)	$	392		$	(59	)	$	788			$	(27	)	$	1,115		$	(126	)	$	989
Deferred premium revenue	$	378		$	(70	)	$	119		$	(6	)	$	312			$	(33	)	$	700		$	(116	)	$	584
Reserves (salvage)(4)	$	(42	)	$	(5	)	$	278		$	(53	)	$	482			$	(10	)	$	650		$	(79	)	$	571
____________________
-1	A risk represents the aggregate of the financial guaranty policies that share the same revenue source for purposes of making Debt Service payments. The ceded number of risks represents the number of risks for which the Company ceded a portion of its exposure.
-2	Includes BIG amounts related to FG VIEs.
-3	Includes excess spread and draws on HELOCs.
-4	See table “Components of net reserves (salvage).”

Fair_Value_Measurement_Tables

Fair Value Measurement (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Information by Credit Spread Type	Information by Credit Spread Type (1)
		As of			As of
		31-Mar-15			31-Dec-14
	Based on actual collateral specific spreads	9	%		9	%
	Based on market indices	81	%		82	%
	Provided by the CDS counterparty	10	%		9	%
	Total	100	%		100	%
	____________________
	(1)    Based on par.
Schedule of example effects of change in gross spreads, company's own credit spread and cost to buy protection on the on the Company affect the amount of premium the company can demand for credit protection
		Scenario 1						Scenario 2
		bps			% of Total			bps			% of Total
	Original gross spread/cash bond price (in bps)	185						500
	Bank profit (in bps)	115			62	%		50			10	%
	Hedge cost (in bps)	30			16	%		440			88	%
	The premium the Company receives per annum (in bps)	40			22	%		10			2	%
Fair Value Hierarchy of Financial Instruments Carried at Fair Value	Fair Value Hierarchy of Financial Instruments Carried at Fair Value
	As of March 31, 2015
						Fair Value Hierarchy
		Fair Value				Level 1				Level 2				Level 3
		(in millions)
	Assets:
	Investment portfolio, available-for-sale:
	Fixed-maturity securities
	Obligations of state and political subdivisions	$	5,458			$	—			$	5,450			$	8
	U.S. government and agencies	497				—				497				—
	Corporate securities	1,399				—				1,320				79
	Mortgage-backed securities:
	RMBS	1,185				—				802				383
	Commercial mortgage-backed securities ("CMBS")	600				—				600				—
	Asset-backed securities	401				—				175				226
	Foreign government securities	293				—				293				—
	Total fixed-maturity securities	9,833				—				9,137				696
	Short-term investments	349				172				177				—
	Other invested assets (1)	107				0				26				81
	Credit derivative assets	77				—				—				77
	FG VIEs’ assets, at fair value (2)	1,495				—				—				1,495
	Other assets	84				30				17				37
	Total assets carried at fair value	$	11,945			$	202			$	9,357			$	2,386
	Liabilities:
	Credit derivative liabilities	$	859			$	—			$	—			$	859
	FG VIEs’ liabilities with recourse, at fair value	1,278				—				—				1,278
	FG VIEs’ liabilities without recourse, at fair value	145				—				—				145
	Total liabilities carried at fair value	$	2,282			$	—			$	—			$	2,282
	Fair Value Hierarchy of Financial Instruments Carried at Fair Value
	As of December 31, 2014
						Fair Value Hierarchy
		Fair Value				Level 1				Level 2				Level 3
		(in millions)
	Assets:
	Investment portfolio, available-for-sale:
	Fixed-maturity securities
	Obligations of state and political subdivisions	$	5,795			$	—			$	5,757			$	38
	U.S. government and agencies	665				—				665				—
	Corporate securities	1,368				—				1,289				79
	Mortgage-backed securities:
	RMBS	1,285				—				860				425
	CMBS	659				—				659				—
	Asset-backed securities	417				—				189				228
	Foreign government securities	302				—				302				—
	Total fixed-maturity securities	10,491				—				9,721				770
	Short-term investments	767				359				408				—
	Other invested assets (1)	100				0				17				83
	Credit derivative assets	68				—				—				68
	FG VIEs’ assets, at fair value (2)	1,398				—				—				1,398
	Other assets	78				26				17				35
	Total assets carried at fair value	$	12,902			$	385			$	10,163			$	2,354
	Liabilities:
	Credit derivative liabilities	$	963			$	—			$	—			$	963
	FG VIEs’ liabilities with recourse, at fair value	1,277				—				—				1,277
	FG VIEs’ liabilities without recourse, at fair value	142				—				—				142
	Total liabilities carried at fair value	$	2,382			$	—			$	—			$	2,382
	____________________
	-1	Includes Level 3 mortgage loans that are recorded at fair value on a non-recurring basis.
	-2	Exclude restricted cash.
Fair Value Assets Measured on Recurring Basis	Fair Value Level 3 Rollforward
	Recurring Basis
	First Quarter 2015
		Fixed-Maturity Securities
		Obligations					Corporate Securities					RMBS					Asset-					Other					FG VIEs’					Other					Credit					FG VIEs' Liabilities					FG VIEs’ Liabilities
		of State and															Backed					Invested					Assets at					Assets					Derivative					with					without
		Political															Securities					Assets					Fair										Asset					Recourse,					Recourse,
		Subdivisions																									Value										(Liability),					at Fair					at Fair
																																					net(5)					Value					Value
		(in millions)
	Fair value as of December 31, 2014	$	38				$	79				$	425				$	228				$	78				$	1,398				$	35				$	(895	)			$	(1,277	)			$	(142	)
	Total pretax realized and unrealized gains/(losses) recorded in:(1)
	Net income (loss)	3			(2	)	2			(2	)	9			(2	)	(2		)	(2	)	(4		)	(2	)	23			(3	)	2			(4	)	124			(6	)	93			(3	)	(5		)	(3	)
	Other comprehensive income (loss)	(2		)			(2		)			5					1					2					—					—					—					—					—
	Purchases	—					—					9					—					—					—					—					—					—					—
	Settlements	(31		)	(7	)	—					(65		)			(1		)			0					(30		)			—					(11		)			37					2
	FG VIE consolidations	—					—					—					—					—					104					—					—					(131		)			—
	FG VIE deconsolidations	—					—					—					—					—					—					—					—					—					—
	Fair value as of March 31, 2015	$	8				$	79				$	383				$	226				$	76				$	1,495				$	37				$	(782	)			$	(1,278	)			$	(145	)
	Change in unrealized gains/(losses) related to financial instruments held as of March 31, 2015	$	0				$	(2	)			$	7				$	1				$	2				$	34				$	2				$	103				$	(6	)			$	(4	)
	Fair Value Level 3 Rollforward
	Recurring Basis
	First Quarter 2014
		Fixed-Maturity Securities
		Obligations					Corporate Securities					RMBS					Asset-Backed Securities					Other					FG VIEs’					Other					Credit					FG VIEs' Liabilities					FG VIEs’ Liabilities
		of State and																				Invested					Assets at					Assets					Derivative					with					without
		Political																				Assets					Fair										Asset					Recourse,					Recourse,
		Subdivisions																									Value										(Liability),					at Fair					at Fair
																																					net(5)					Value					Value
		(in millions)
	Fair value as of December 31, 2013	$	36				$	136				$	290				268					$	2				$	2,565				$	46				$	(1,693	)			$	(1,790	)			$	(1,081	)
	Total pretax realized and unrealized gains/(losses) recorded in:(1)
	Net income (loss)	1			(2	)	3			(2	)	4			(2	)	7			(2	)	—					82			(3	)	(9		)	(4	)	(211		)	(6	)	(72		)	(3	)	(9		)	(3	)
	Other comprehensive income (loss)	1					4					14					8					1					—					—					—					—					—
	Purchases	—					—					53					—					45			(7	)	—					—					—					—					—
	Settlements	—					(5		)			(15		)			(31		)			—					(286		)			—					(19		)			269					12
	FG VIE consolidations	—					—					—					—					—					—					—					—					—					—
	FG VIE deconsolidations	—					—					13					—					—					(1,104		)			—					—					247					977
	Fair value as of March 31, 2014	$	38				$	138				$	359				$	252				$	48				$	1,257				$	37				$	(1,923	)			$	(1,346	)			$	(101	)
	Change in unrealized gains/(losses) related to financial instruments held as of March 31, 2014	$	1				$	4				$	15				$	7				$	1				$	25				$	(9	)			$	(232	)			$	(28	)			$	(10	)
	______________
	-1	Realized and unrealized gains (losses) from changes in values of Level 3 financial instruments represent gains (losses) from changes in values of those financial instruments only for the periods in which the instruments were classified as Level 3.
	-2	Included in net realized investment gains (losses) and net investment income.
	-3	Included in fair value gains (losses) on FG VIEs.
	-4	Recorded in fair value gains (losses) on CCS.
	-5	Represents net position of credit derivatives. The consolidated balance sheet presents gross assets and liabilities based on net counterparty exposure.
	-6	Reported in net change in fair value of credit derivatives.
	-7	Includes a non-cash transaction.
Fair Value, Liabilities Measured on Recurring Basis	Fair Value Level 3 Rollforward
	Recurring Basis
	First Quarter 2015
		Fixed-Maturity Securities
		Obligations					Corporate Securities					RMBS					Asset-					Other					FG VIEs’					Other					Credit					FG VIEs' Liabilities					FG VIEs’ Liabilities
		of State and															Backed					Invested					Assets at					Assets					Derivative					with					without
		Political															Securities					Assets					Fair										Asset					Recourse,					Recourse,
		Subdivisions																									Value										(Liability),					at Fair					at Fair
																																					net(5)					Value					Value
		(in millions)
	Fair value as of December 31, 2014	$	38				$	79				$	425				$	228				$	78				$	1,398				$	35				$	(895	)			$	(1,277	)			$	(142	)
	Total pretax realized and unrealized gains/(losses) recorded in:(1)
	Net income (loss)	3			(2	)	2			(2	)	9			(2	)	(2		)	(2	)	(4		)	(2	)	23			(3	)	2			(4	)	124			(6	)	93			(3	)	(5		)	(3	)
	Other comprehensive income (loss)	(2		)			(2		)			5					1					2					—					—					—					—					—
	Purchases	—					—					9					—					—					—					—					—					—					—
	Settlements	(31		)	(7	)	—					(65		)			(1		)			0					(30		)			—					(11		)			37					2
	FG VIE consolidations	—					—					—					—					—					104					—					—					(131		)			—
	FG VIE deconsolidations	—					—					—					—					—					—					—					—					—					—
	Fair value as of March 31, 2015	$	8				$	79				$	383				$	226				$	76				$	1,495				$	37				$	(782	)			$	(1,278	)			$	(145	)
	Change in unrealized gains/(losses) related to financial instruments held as of March 31, 2015	$	0				$	(2	)			$	7				$	1				$	2				$	34				$	2				$	103				$	(6	)			$	(4	)
	Fair Value Level 3 Rollforward
	Recurring Basis
	First Quarter 2014
		Fixed-Maturity Securities
		Obligations					Corporate Securities					RMBS					Asset-Backed Securities					Other					FG VIEs’					Other					Credit					FG VIEs' Liabilities					FG VIEs’ Liabilities
		of State and																				Invested					Assets at					Assets					Derivative					with					without
		Political																				Assets					Fair										Asset					Recourse,					Recourse,
		Subdivisions																									Value										(Liability),					at Fair					at Fair
																																					net(5)					Value					Value
		(in millions)
	Fair value as of December 31, 2013	$	36				$	136				$	290				268					$	2				$	2,565				$	46				$	(1,693	)			$	(1,790	)			$	(1,081	)
	Total pretax realized and unrealized gains/(losses) recorded in:(1)
	Net income (loss)	1			(2	)	3			(2	)	4			(2	)	7			(2	)	—					82			(3	)	(9		)	(4	)	(211		)	(6	)	(72		)	(3	)	(9		)	(3	)
	Other comprehensive income (loss)	1					4					14					8					1					—					—					—					—					—
	Purchases	—					—					53					—					45			(7	)	—					—					—					—					—
	Settlements	—					(5		)			(15		)			(31		)			—					(286		)			—					(19		)			269					12
	FG VIE consolidations	—					—					—					—					—					—					—					—					—					—
	FG VIE deconsolidations	—					—					13					—					—					(1,104		)			—					—					247					977
	Fair value as of March 31, 2014	$	38				$	138				$	359				$	252				$	48				$	1,257				$	37				$	(1,923	)			$	(1,346	)			$	(101	)
	Change in unrealized gains/(losses) related to financial instruments held as of March 31, 2014	$	1				$	4				$	15				$	7				$	1				$	25				$	(9	)			$	(232	)			$	(28	)			$	(10	)
	______________
	-1	Realized and unrealized gains (losses) from changes in values of Level 3 financial instruments represent gains (losses) from changes in values of those financial instruments only for the periods in which the instruments were classified as Level 3.
	-2	Included in net realized investment gains (losses) and net investment income.
	-3	Included in fair value gains (losses) on FG VIEs.
	-4	Recorded in fair value gains (losses) on CCS.
	-5	Represents net position of credit derivatives. The consolidated balance sheet presents gross assets and liabilities based on net counterparty exposure.
	-6	Reported in net change in fair value of credit derivatives.
	-7	Includes a non-cash transaction.
Schedule of Quantitative Information About Level 3 Assets, Fair Value Measurements	Quantitative Information About Level 3 Fair Value Inputs
	At March 31, 2015
	Financial Instrument Description (1)		Fair Value at				Significant Unobservable Inputs		Range						Weighted Average as a Percentage of Current Par Outstanding
			March 31, 2015
			(in millions)
	Assets:
	Fixed-maturity securities:
	Obligations of state and political subdivisions		$	8			Rate of inflation		1		%	-	3.00%		2.00%
							Cash flow receipts		0.5		%	-	20.90%		12.90%
							Yield		4.60%
							Collateral recovery period		4 months			-	8.3 years		4.3 years
	Corporate securities		79				Yield		18.00%
	RMBS		383				CPR		0.3		%	-	7.50%		3.40%
							CDR		2.4		%	-	11.60%		5.50%
							Loss severity		50		%	-	100.00%		72.40%
							Yield		4.2		%	-	10.00%		5.90%
	Asset-backed securities:
	Investor owned utility		96				Cash flow receipts		100.00%
							Collateral recovery period		3.8 years
							Discount factor		7.00%
	Triple-X life insurance transactions		130				Yield		6.80%
	Other invested assets		81				Discount for lack of liquidity		20.00%
							Recovery on delinquent loans		40.00%
							Default rates		0		%	-	7.00%		6.10%
							Loss severity		40		%	-	75.00%		68.70%
							Prepayment speeds		6		%	-	15.00%		12.00%
							Net asset value (per share)		$	966		-	$1,147		$1,046
	FG VIEs’ assets, at fair value		1,495				CPR		0.3		%	-	11.00%		2.60%
							CDR		1.7		%	-	13.10%		4.20%
							Loss severity		36		%	-	100.00%		64.20%
							Yield		2.7		%	-	16.70%		6.40%
	Financial Instrument Description (1)		Fair Value at			Significant Unobservable Inputs		Range						Weighted Average as a Percentage of Current Par Outstanding
			March 31, 2015
			(in millions)
	Other assets		37			Quotes from third party pricing		$	51		-	$60		$56
						Term (years)		5 years
	Liabilities:
	Credit derivative liabilities, net		(782	)		Year 1 loss estimates		0		%	-	50.00%		1.70%
						Hedge cost (in bps)		15			-	255.8		57.4
						Bank profit (in bps)		1			-	990		124.8
						Internal floor (in bps)		7			-	100		16.3
						Internal credit rating		AAA			-	CCC		AA
	FG VIEs’ liabilities, at fair value		(1,423	)		CPR		0.3		%	-	11.00%		2.60%
						CDR		1.7		%	-	13.10%		4.20%
						Loss severity		36		%	-	100.00%		64.20%
						Yield		2.7		%	-	16.70%		5.50%
	___________________
	-1	Discounted cash flow is used as valuation technique for all financial instruments.
	Quantitative Information About Level 3 Fair Value Inputs
	At December 31, 2014
	Financial Instrument Description (1)		Fair Value at				Significant Unobservable Inputs		Range						Weighted Average as a Percentage of Current Par Outstanding
			December 31, 2014
			(in millions)
	Assets:
	Fixed-maturity securities:
	Obligations of state and political subdivisions		$	38			Rate of inflation		1		%	-	3.00%		2.00%
							Cash flow receipts		0.5		%	-	74.30%		63.00%
							Discount rates		4.6		%	-	8.00%		7.30%
							Collateral recovery period		1 month			-	34 years		28 years
	Corporate securities		79				Yield		17.80%
	RMBS		425				CPR		0.3		%	-	8.10%		3.30%
							CDR		2.7		%	-	10.60%		5.30%
							Loss severity		52.6		%	-	100.00%		75.20%
							Yield		4.7		%	-	11.70%		6.40%
Asset-backed securities:
Investor owned utility		95				Cash flow receipts		100%
						Collateral recovery period		4 years
						Discount factor		7.00%
Triple-X life insurance transactions		133				Yield		7.30%
Other invested assets		83				Discount for lack of liquidity		20.00%
						Recovery on delinquent loans		40.00%
						Default rates		0		%	-	7.00%		5.80%
						Loss severity		40		%	-	75.00%		68.30%
						Prepayment speeds		5		%	-	15.00%		12.30%
						Net asset value (per share)		$	965		-	$1,159		$1,082
FG VIEs’ assets, at fair value		1,398				CPR		0.3		%	-	11.00%		3.30%
						CDR		1.6		%	-	11.80%		5.10%
						Loss severity		40		%	-	100.00%		82.20%
						Yield		2.7		%	-	17.70%		7.90%
Financial Instrument Description (1)		Fair Value at			Significant Unobservable Inputs		Range					Weighted Average as a Percentage of Current Par Outstanding
		December 31, 2014
		(in millions)
Other assets		35			Quotes from third party pricing		$52		-	$61		$57
					Term (years)		5 years
Liabilities:
Credit derivative liabilities, net		(895	)		Year 1 loss estimates		0	%	-	93.00%		2.10%
					Hedge cost (in bps)		20		-	243.8		61.5
					Bank profit (in bps)		1		-	994.4		127
					Internal floor (in bps)		7		-	100		15.9
					Internal credit rating		AAA		-	CCC		AA+
FG VIEs’ liabilities, at fair value		(1,419	)		CPR		0.3	%	-	11.00%		3.30%
					CDR		1.6	%	-	11.80%		5.10%
					Loss severity		40	%	-	100.00%		82.20%
					Yield		2.7	%	-	17.70%		5.80%
____________________
-1	Discounted cash flow is used as valuation technique for all financial instruments.
Schedule of Quantitative Information About Level 3 Liabilities, Fair Value Measurements	At March 31, 2015
	Financial Instrument Description (1)		Fair Value at				Significant Unobservable Inputs		Range						Weighted Average as a Percentage of Current Par Outstanding
			March 31, 2015
			(in millions)
	Assets:
	Fixed-maturity securities:
	Obligations of state and political subdivisions		$	8			Rate of inflation		1		%	-	3.00%		2.00%
							Cash flow receipts		0.5		%	-	20.90%		12.90%
							Yield		4.60%
							Collateral recovery period		4 months			-	8.3 years		4.3 years
	Corporate securities		79				Yield		18.00%
	RMBS		383				CPR		0.3		%	-	7.50%		3.40%
							CDR		2.4		%	-	11.60%		5.50%
							Loss severity		50		%	-	100.00%		72.40%
							Yield		4.2		%	-	10.00%		5.90%
	Asset-backed securities:
	Investor owned utility		96				Cash flow receipts		100.00%
							Collateral recovery period		3.8 years
							Discount factor		7.00%
	Triple-X life insurance transactions		130				Yield		6.80%
	Other invested assets		81				Discount for lack of liquidity		20.00%
							Recovery on delinquent loans		40.00%
							Default rates		0		%	-	7.00%		6.10%
							Loss severity		40		%	-	75.00%		68.70%
							Prepayment speeds		6		%	-	15.00%		12.00%
							Net asset value (per share)		$	966		-	$1,147		$1,046
	FG VIEs’ assets, at fair value		1,495				CPR		0.3		%	-	11.00%		2.60%
							CDR		1.7		%	-	13.10%		4.20%
							Loss severity		36		%	-	100.00%		64.20%
							Yield		2.7		%	-	16.70%		6.40%
	Financial Instrument Description (1)		Fair Value at			Significant Unobservable Inputs		Range						Weighted Average as a Percentage of Current Par Outstanding
			March 31, 2015
			(in millions)
	Other assets		37			Quotes from third party pricing		$	51		-	$60		$56
						Term (years)		5 years
	Liabilities:
	Credit derivative liabilities, net		(782	)		Year 1 loss estimates		0		%	-	50.00%		1.70%
						Hedge cost (in bps)		15			-	255.8		57.4
						Bank profit (in bps)		1			-	990		124.8
						Internal floor (in bps)		7			-	100		16.3
						Internal credit rating		AAA			-	CCC		AA
	FG VIEs’ liabilities, at fair value		(1,423	)		CPR		0.3		%	-	11.00%		2.60%
						CDR		1.7		%	-	13.10%		4.20%
						Loss severity		36		%	-	100.00%		64.20%
						Yield		2.7		%	-	16.70%		5.50%
	___________________
	-1	Discounted cash flow is used as valuation technique for all financial instruments.
	Quantitative Information About Level 3 Fair Value Inputs
	At December 31, 2014
	Financial Instrument Description (1)		Fair Value at				Significant Unobservable Inputs		Range						Weighted Average as a Percentage of Current Par Outstanding
			December 31, 2014
			(in millions)
	Assets:
	Fixed-maturity securities:
	Obligations of state and political subdivisions		$	38			Rate of inflation		1		%	-	3.00%		2.00%
							Cash flow receipts		0.5		%	-	74.30%		63.00%
							Discount rates		4.6		%	-	8.00%		7.30%
							Collateral recovery period		1 month			-	34 years		28 years
	Corporate securities		79				Yield		17.80%
	RMBS		425				CPR		0.3		%	-	8.10%		3.30%
							CDR		2.7		%	-	10.60%		5.30%
							Loss severity		52.6		%	-	100.00%		75.20%
							Yield		4.7		%	-	11.70%		6.40%
	Asset-backed securities:
Investor owned utility		95				Cash flow receipts		100%
						Collateral recovery period		4 years
						Discount factor		7.00%
Triple-X life insurance transactions		133				Yield		7.30%
Other invested assets		83				Discount for lack of liquidity		20.00%
						Recovery on delinquent loans		40.00%
						Default rates		0		%	-	7.00%		5.80%
						Loss severity		40		%	-	75.00%		68.30%
						Prepayment speeds		5		%	-	15.00%		12.30%
						Net asset value (per share)		$	965		-	$1,159		$1,082
FG VIEs’ assets, at fair value		1,398				CPR		0.3		%	-	11.00%		3.30%
						CDR		1.6		%	-	11.80%		5.10%
						Loss severity		40		%	-	100.00%		82.20%
						Yield		2.7		%	-	17.70%		7.90%
Financial Instrument Description (1)		Fair Value at			Significant Unobservable Inputs		Range					Weighted Average as a Percentage of Current Par Outstanding
		December 31, 2014
		(in millions)
Other assets		35			Quotes from third party pricing		$52		-	$61		$57
					Term (years)		5 years
Liabilities:
Credit derivative liabilities, net		(895	)		Year 1 loss estimates		0	%	-	93.00%		2.10%
					Hedge cost (in bps)		20		-	243.8		61.5
					Bank profit (in bps)		1		-	994.4		127
					Internal floor (in bps)		7		-	100		15.9
					Internal credit rating		AAA		-	CCC		AA+
FG VIEs’ liabilities, at fair value		(1,419	)		CPR		0.3	%	-	11.00%		3.30%
					CDR		1.6	%	-	11.80%		5.10%
					Loss severity		40	%	-	100.00%		82.20%
					Yield		2.7	%	-	17.70%		5.80%
____________________
-1	Discounted cash flow is used as valuation technique for all financial instruments.
Fair Value of Financial Instruments	Fair Value of Financial Instruments
		As of								As of
		31-Mar-15								31-Dec-14
		Carrying				Estimated				Carrying				Estimated
		Amount				Fair Value				Amount				Fair Value
		(in millions)
	Assets:
	Fixed-maturity securities	$	9,833			$	9,833			$	10,491			$	10,491
	Short-term investments	349				349				767				767
	Other invested assets	114				116				108				110
	Credit derivative assets	77				77				68				68
	FG VIEs’ assets, at fair value	1,495				1,495				1,398				1,398
	Other assets	189				189				184				184
	Liabilities:
	Financial guaranty insurance contracts(1)	3,719				6,343				3,823				6,205
	Long-term debt	1,304				1,609				1,303				1,603
	Credit derivative liabilities	859				859				963				963
	FG VIEs’ liabilities with recourse, at fair value	1,278				1,278				1,277				1,277
	FG VIEs’ liabilities without recourse, at fair value	145				145				142				142
	Other liabilities	72				72				27				27
	____________________
	-1	Carrying amount includes the assets and liabilities related to financial guaranty insurance contract premiums, losses, and salvage and subrogation and other recoverables net of reinsurance.

Financial_Guaranty_Contracts_A1

Financial Guaranty Contracts Accounted for as Credit Derivatives (Tables)	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Credit Derivatives Subordination and Ratings and Net Par Outstanding by Internal Rating	Distribution of Credit Derivative Net Par Outstanding by Internal Rating
			As of March 31, 2015							As of December 31, 2014
	Ratings		Net Par				% of Total			Net Par				% of Total
			Outstanding							Outstanding
			(dollars in millions)
	AAA		$	19,132			60.3	%		$	21,817			62.3	%
	AA		5,195				16.4			5,398				15.4
	A		1,865				5.9			1,982				5.7
	BBB		2,616				8.2			2,774				8
	BIG		2,923				9.2			3,025				8.6
	Credit derivative net par outstanding		$	31,731			100	%		$	34,996			100	%
	Credit Derivatives
	Subordination and Ratings
			As of March 31, 2015												As of December 31, 2014
	Asset Type		Net Par				Original			Current			Weighted		Net Par			Original		Current		Weighted
			Outstanding				Subordination(1)			Subordination(1)			Average		Outstanding			Subordination(1)		Subordination(1)		Average
													Credit									Credit
													Rating									Rating
			(dollars in millions)
	Pooled corporate obligations:
	Collateralized loan obligation/collateral bond obligations		$	10,372			32	%		37.7	%		AAA		$	11,688		32	%	36.9	%	AAA
	Synthetic investment grade pooled corporate		6,363				22.3			20.2			AAA		7,640			22.6		20.6		AAA
	TruPS CDOs		2,948				45.6			37.5			BBB-		3,119			45.3		35.8		BBB-
	Market value CDOs of corporate obligations		1,052				17			15.7			AAA		1,174			19.1		20.7		AAA
	Total pooled corporate obligations		20,735				30.2			31.2			AAA		23,621			30.1		30.7		AAA
	U.S. RMBS:
	Option ARM and Alt-A first lien		1,321				16.2			10.5			BB+		1,378			16.3		10.7		BB+
	Subprime first lien		1,315				31.3			49.9			A		1,366			31.1		50.5		A
	Prime first lien		213				10.9			0			B		223			10.9		0		B
	Closed-end second lien		19				—			—			CCC		19			—		—		CCC
	Total U.S. RMBS		2,868				24.8			33.3			BBB		2,986			24.8		33.9		BBB
	CMBS		1,785				35.9			45.5			AAA		1,952			35.3		43.6		AAA
	Other		6,343				—			—			A		6,437			—		—		A
	Total		$	31,731									AA		$	34,996						AA+
	____________________
	-1	Represents the sum of subordinate tranches and over-collateralization and does not include any benefit from excess interest collections that may be used to absorb losses.
Net Change in Fair Value of Credit Derivatives	Net Change in Fair Value of Credit Derivatives Gain (Loss)
		First Quarter
		2015				2014
		(in millions)
	Realized gains on credit derivatives (1)	$	23			$	20
	Net credit derivative losses (paid and payable) recovered and recoverable and other settlements	(2		)		(1		)
	Realized gains (losses) and other settlements on credit derivatives	21				19
	Net change in unrealized gains (losses) on credit derivatives:
	Pooled corporate obligations	17				(58		)
	U.S. RMBS	75				(140		)
	CMBS	0				0
	Other	11				(32		)
	Net change in unrealized gains (losses) on credit derivatives	103				(230		)
	Net change in fair value of credit derivatives	$	124			$	(211	)
	____________________
	-1	Includes realized gain due to terminations of CDS contracts of $11 million and $0.2 million for First Quarter 2015 and First Quarter 2014, respectively. Net par of $93 million and $1.1 billion were terminated in First Quarter 2015 and First Quarter 2014, respectively. CDS terminations reflect a payment received from the resolution of a dispute related to a termination of CDS in 2008.
CDS Spread on AGC and AGM	Five-Year CDS Spread
	on AGC and AGM
	Quoted price of CDS contract (in basis points)
		As of			As of			As of			As of
		31-Mar-15			31-Dec-14			31-Mar-14			31-Dec-13
	AGC	317			323			291			460
	AGM	341			325			305			525
	One-Year CDS Spread
	on AGC and AGM
	Quoted price of CDS contract (in basis points)
		As of			As of			As of			As of
		31-Mar-15			31-Dec-14			31-Mar-14			31-Dec-13
	AGC	60			80			55			185
	AGM	80			85			70			220
Fair Value of Credit Derivatives and Effect of AGC and AGM Credit Spreads	Fair Value of Credit Derivatives Assets (Liabilities)
	and Effect of AGC and AGM
	Credit Spreads
		As of				As of
		31-Mar-15				31-Dec-14
		(in millions)
	Fair value of credit derivatives before effect of AGC and AGM credit spreads	$	(1,820	)		$	(2,029	)
	Plus: Effect of AGC and AGM credit spreads	1,038				1,134
	Net fair value of credit derivatives	$	(782	)		$	(895	)
Net Fair Value and Expected Losses of Credit Derivatives by Sector	Net Fair Value and Expected Losses
	of Credit Derivatives by Sector
			Fair Value of Credit Derivative								Expected Loss to be (Paid) Recovered (1)
			Asset (Liability), net
	Asset Type		As of				As of				As of				As of
			31-Mar-15				31-Dec-14				31-Mar-15				31-Dec-14
			(in millions)
	Pooled corporate obligations		$	(22	)		$	(49	)		$	(13	)		$	(23	)
	U.S. RMBS		(419		)		(494		)		(66		)		(73		)
	CMBS		0				0				—				—
	Other		(341		)		(352		)		37				38
	Total		$	(782	)		$	(895	)		$	(42	)		$	(58	)
	____________________
	(1)	Includes R&W benefit of $75 million as of March 31, 2015 and $86 million as of December 31, 2014.
Effects of Changes in Credit Spread	Effect of Changes in Credit Spread
	As of March 31, 2015
	Credit Spreads(1)		Estimated Net				Estimated Change
			Fair Value				in Gain/(Loss)
			(Pre-Tax)				(Pre-Tax)
			(in millions)
	100% widening in spreads		$	(1,590	)		$	(808	)
	50% widening in spreads		(1,186		)		(404		)
	25% widening in spreads		(986		)		(204		)
	10% widening in spreads		(864		)		(82		)
	Base Scenario		(782		)		—
	10% narrowing in spreads		(706		)		76
	25% narrowing in spreads		(593		)		189
	50% narrowing in spreads		(407		)		375
	____________________
	-1	Includes the effects of spreads on both the underlying asset classes and the Company’s own credit spread.

Consolidated_Variable_Interest1

Consolidated Variable Interest Entities (Tables)	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Consolidated FG VIE's	Consolidated FG VIEs
	By Type of Collateral
		As of March 31, 2015							As of December 31, 2014
		Assets				Liabilities			Assets		Liabilities
		(in millions)
	With recourse:
	U.S. RMBS first lien	$	739			$	591		$	632	$	581
	U.S. RMBS second lien	228				322			238		327
	Other	365				365			369		369
	Total with recourse	1,332				1,278			1,239		1,277
	Without recourse	167				145			163		142
	Total	$	1,499			$	1,423		$	1,402	$	1,419
	Number of FG VIEs Consolidated
		First Quarter
		2015			2014
	Beginning of the period, December 31	32			40
	Consolidated (1)	1			—
	Deconsolidated (1)	—			(7	)
	Matured	—			(2	)
	End of the period, March 31	33			31
	____________________
	-1	Net loss on consolidation was $26 million in First Quarter 2015, and net gain on deconsolidation was $120 million in First Quarter 2014, and recorded in “fair value gains (losses) on FG VIEs” in the consolidated statement of operations.
	Effect of Consolidating FG VIEs on Net Income,
	Cash Flows From Operating Activities and Shareholders’ Equity
		First Quarter
		2015				2014
	Net earned premiums	$	(5	)		$	(17	)
	Net investment income	(3		)		(3		)
	Fair value gains (losses) on FG VIEs	(7		)		157
	Other income (loss)	0				(2		)
	Loss and LAE	5				(1		)
	Effect on net income before tax	(10		)		134
	Less: tax provision (benefit)	(4		)		47
	Effect on net income (loss)	$	(6	)		$	87
	Effect on cash flows from operating activities	$	18			$	(8	)
		As of				As of
		31-Mar-15				31-Dec-14
		(in millions)
	Effect on shareholders’ equity (decrease) increase	$	(49	)		$	(44	)

Investments_and_Cash_Tables

Investments and Cash (Tables)	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Net Investment Income	Net Investment Income
		First Quarter
		2015			2014
		(in millions)
	Income from fixed-maturity securities managed by third parties	$	82		$	80
	Income from internally managed securities:
	Fixed maturities	15			20
	Other invested assets	6			5
	Gross investment income	103			105
	Investment expenses	(2		)	(2		)
	Net investment income	$	101		$	103
Net Realized Investment Gains (Losses)	Net Realized Investment Gains (Losses)
		First Quarter
		2015			2014
		(in millions)
	Gross realized gains on available-for-sale securities	$	24		$	4
	Gross realized gains on other assets in investment portfolio	1			5
	Gross realized losses on available-for-sale securities	(1		)	(2		)
	Gross realized losses on other assets in investment portfolio	(1		)	0
	Other-than-temporary impairment	(7		)	(5		)
	Net realized investment gains (losses)	$	16		$	2
Roll Forward of Credit Losses in the Investment Portfolio	Roll Forward of Credit Losses
	in the Investment Portfolio
		First Quarter
		2015			2014
		(in millions)
	Balance, beginning of period	$	124		$	80
	Additions for credit losses on securities for which an other-than-temporary-impairment was not previously recognized	—			1
	Reductions for securities sold and other settlement during the period	(21		)	—
	Additions for credit losses on securities for which an other-than-temporary-impairment was previously recognized	3			4
	Balance, end of period	$	106		$	85
Fixed Maturity Securities and Short Term Investments by Security Type	Fixed-Maturity Securities and Short-Term Investments
	by Security Type
	As of March 31, 2015
	Investment Category		Percent		Amortized			Gross		Gross			Estimated		AOCI(2)			Weighted
			of		Cost			Unrealized		Unrealized			Fair		Gain			Average
			Total(1)					Gains		Losses			Value		(Loss) on			Credit
															Securities			Rating
															with			(3)
															Other-Than-Temporary Impairment
			(dollars in millions)
	Fixed-maturity securities:
	Obligations of state and political subdivisions		52	%	$	5,099		$	361	$	(2	)	$	5,458	$	4		AA
	U.S. government and agencies		5		464			33		0			497		—			AA+
	Corporate securities		14		1,340			65		(6		)	1,399		(4		)	A
	Mortgage-backed securities(4):		0
	RMBS		12		1,145			56		(16		)	1,185		5			A
	CMBS		6		573			27		0			600		—			AAA
	Asset-backed securities		4		394			7		—			401		3			BBB-
	Foreign government securities		3		295			6		(8		)	293		0			AA+
	Total fixed-maturity securities		96		9,310			555		(32		)	9,833		8			AA-
	Short-term investments		4		349			0		0			349		—			AAA
	Total investment portfolio		100	%	$	9,659		$	555	$	(32	)	$	10,182	$	8		AA-
	Fixed-Maturity Securities and Short-Term Investments
	by Security Type
	As of December 31, 2014
	Investment Category		Percent		Amortized			Gross		Gross			Estimated		AOCI			Weighted
			of		Cost			Unrealized		Unrealized			Fair		Gain			Average
			Total(1)					Gains		Losses			Value		(Loss) on			Credit
															Securities			Rating
															with			(3)
															Other-Than-Temporary Impairment
			(dollars in millions)
	Fixed-maturity securities:
	Obligations of state and political subdivisions		50	%	$	5,416		$	380	$	(1	)	$	5,795	$	7		AA
	U.S. government and agencies		6		635			31		(1		)	665		—			AA+
	Corporate securities		12		1,320			53		(5		)	1,368		(2		)	A
	Mortgage-backed securities(4):
	RMBS		12		1,255			51		(21		)	1,285		0			A-
	CMBS		6		639			20		0			659		—			AAA
	Asset-backed securities		4		411			9		(3		)	417		3			BBB-
	Foreign government securities		3		296			8		(2		)	302		—			AA+
	Total fixed-maturity securities		93		9,972			552		(33		)	10,491		8			AA-
	Short-term investments		7		767			0		0			767		0			AA+
	Total investment portfolio		100	%	$	10,739		$	552	$	(33	)	$	11,258	$	8		AA-
	____________________
	-1	Based on amortized cost.
	-2	Accumulated OCI. See also Note 17, Shareholders' Equity.
	-3	Ratings in the tables above represent the lower of the Moody’s and S&P classifications except for bonds purchased for loss mitigation or risk management strategies, which use internal ratings classifications. The Company’s portfolio consists primarily of high-quality, liquid instruments.
	-4	Government-agency obligations were approximately 47% of mortgage backed securities as of March 31, 2015 and 44% as of December 31, 2014 based on fair value.
Fixed Maturity Securities Gross Unrealized Loss by Length of Time	Fixed-Maturity Securities
	Gross Unrealized Loss by Length of Time
	As of March 31, 2015
		Less than 12 months						12 months or more					Total
		Fair			Unrealized			Fair		Unrealized			Fair		Unrealized
		Value			Loss			Value		Loss			Value		Loss
		(dollars in millions)
	Obligations of state and political subdivisions	$	189		$	(2	)	$	5	$	0		$	194	$	(2	)
	U.S. government and agencies	26			0			12		0			38		0
	Corporate securities	194			(6		)	5		0			199		(6		)
	Mortgage-backed securities:
	RMBS	94			(1		)	85		(15		)	179		(16		)
	CMBS	21			0			2		0			23		0
	Asset-backed securities	—			—			—		—			—		—
	Foreign government securities	156			(8		)	—		—			156		(8		)
	Total	$	680		$	(17	)	$	109	$	(15	)	$	789	$	(32	)
	Number of securities (1)				166					24					187
	Number of securities with other-than-temporary impairment				2					3					5
	Fixed-Maturity Securities
	Gross Unrealized Loss by Length of Time
	As of December 31, 2014
		Less than 12 months						12 months or more					Total
		Fair			Unrealized			Fair		Unrealized			Fair		Unrealized
		Value			Loss			Value		Loss			Value		Loss
		(dollars in millions)
	Obligations of state and political subdivisions	$	64		$	0		$	25	$	(1	)	$	89	$	(1	)
	U.S. government and agencies	139			0			68		(1		)	207		(1		)
	Corporate securities	189			(3		)	104		(2		)	293		(5		)
	Mortgage-backed securities:
	RMBS	205			(3		)	159		(18		)	364		(21		)
	CMBS	36			0			19		0			55		0
	Asset-backed securities	56			(2		)	18		(1		)	74		(3		)
	Foreign government securities	108			(2		)	0		0			108		(2		)
	Total	$	797		$	(10	)	$	393	$	(23	)	$	1,190	$	(33	)
	Number of securities (1)				125					82					198
	Number of securities with other-than-temporary impairment				3					7					10
	___________________
	-1	The number of securities does not add across because lots of the same securities have been purchased at different times and appear in both categories above (i.e. Less than 12 months and 12 months or more). If a security appears in both categories, it is counted only once in the total column.
Distribution of Fixed Maturity Securities by Contractual Maturity	Distribution of Fixed-Maturity Securities
	by Contractual Maturity
	As of March 31, 2015
		Amortized			Estimated
		Cost			Fair Value
		(in millions)
	Due within one year	$	156		$	158
	Due after one year through five years	1,706			1,763
	Due after five years through 10 years	2,146			2,288
	Due after 10 years	3,584			3,839
	Mortgage-backed securities:
	RMBS	1,145			1,185
	CMBS	573			600
	Total	$	9,310		$	9,833
Internally Managed Investment Portfolio	Internally Managed Portfolio
	Carrying Value
		As of			As of
		31-Mar-15			31-Dec-14
		(in millions)
	Assets purchased for loss mitigation and other risk management purposes:
	Fixed-maturity securities	721			835
	Other invested assets	41			46
	Other	91			79
	Total	$	853		$	960

Insurance_Company_Regulatory_R1

Insurance Company Regulatory Requirements (Tables)	3 Months Ended
	Mar. 31, 2015
Insurance Company Regulatory Requirements [Abstract]
Schedule of Dividends Paid by Insurance Company Subsidiaries	Dividends and Surplus Notes
	By Insurance Company Subsidiaries
		First Quarter
		2015		2014
		(in millions)
	Dividends paid by AGC to AGUS	$	20	$	—
	Dividends paid by AGM to AGMH	66		—
	Dividends paid by AG Re to AGL	50		62
	Repayment of surplus note by AGM to AGMH	25		25

Income_Taxes_Tables

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Effective Tax Rate Reconciliation	Effective Tax Rate Reconciliation
		First Quarter
		2015			2014
		(in millions)
	Expected tax provision (benefit) at statutory rates in taxable jurisdictions	$	77		$	38
	Tax-exempt interest	(14		)	(14		)
	Change in liability for uncertain tax positions	1			1
	Other	1			2
	Total provision (benefit) for income taxes	$	65		$	27
	Effective tax rate	24.2		%	38.8		%
Pretax Income (Loss) by Tax Jurisdiction	Pretax Income (Loss) by Tax Jurisdiction
		First Quarter
		2015			2014
		(in millions)
	United States	$	223		$	113
	Bermuda	50			(37		)
	U.K.	(7		)	(7		)
	Total	$	266		$	69
Revenue by Tax Jurisdiction	Revenue by Tax Jurisdiction
		First Quarter
		2015			2014
		(in millions)
	United States	$	300		$	195
	Bermuda	73			1
	U.K.	(4		)	(1		)
	Total	$	369		$	195

Reinsurance_and_Other_Monoline1

Reinsurance and Other Monoline Exposures (Tables)	3 Months Ended
	Mar. 31, 2015
Insurance [Abstract]
Effects of Reinsurance on Statement of Operations	Effect of Reinsurance on Statement of Operations
		First Quarter
		2015				2014
		(in millions)
	Premiums Written:
	Direct	$	29			$	31
	Assumed(1)	3				(1		)
	Ceded	0				(24		)
	Net	$	32			$	6
	Premiums Earned:
	Direct	$	148			$	140
	Assumed	10				11
	Ceded	(16		)		(19		)
	Net	$	142			$	132
	Loss and LAE:
	Direct	$	26			$	34
	Assumed	(7		)		6
	Ceded	(1		)		1
	Net	$	18			$	41
	____________________
	-1	Negative assumed premiums written were due to change in expected Debt Service schedules.
Exposure by Reinsurer	Exposure by Reinsurer
			Ratings at				Par Outstanding (1)
			May 6, 2015				As of March 31, 2015
	Reinsurer		Moody’s		S&P		Ceded Par			Second-to-			Assumed Par
			Reinsurer		Reinsurer		Outstanding			Pay Insured			Outstanding
			Rating		Rating					Par
										Outstanding
			(dollars in millions)
	American Overseas Reinsurance Company Limited (f/k/a Ram Re)		WR (2)		WR		$	6,363		$	—		$	30
	Tokio Marine & Nichido Fire Insurance Co., Ltd.		Aa3 (3)		AA- (3)		5,006			—			—
	Radian Asset (4)		WR		NR		3,984			18			620
	Syncora Guarantee Inc.		WR		WR		3,522			1,451			160
	Mitsui Sumitomo Insurance Co. Ltd.		A1		A+ (3)		1,995			—			—
	ACA Financial Guaranty Corp.		NR (5)		WR		745			1			—
	Swiss Reinsurance Co.		Aa3		AA-		91			—			—
	Ambac		WR		WR		82			4,796			13,281
	NPFGC (6)		A3		AA-		—			6,061			5,724
	MBIA		-7		-7		—			2,465			484
	Financial Guaranty Insurance Co.		WR		WR		—			2,008			809
	Ambac Assurance Corp. Segregated Account		NR		NR		—			105			936
	CIFG Assurance North America Inc.		WR		WR		—			102			4,177
	Other		Various		Various		199			804			45
	Total						$	21,987		$	17,811		$	26,266
	____________________
	-1	Includes par related to insured credit derivatives.
	(2)    Represents “Withdrawn Rating.”
	(3)    The Company has structural collateral agreements satisfying the triple-A credit requirement of S&P and/or Moody’s.
	-4	On April 1, 2015, AGC consummated the acquisition of Radian Asset and merged Radian Asset with and into AGC, with AGC as the surviving company of the merger.
	(5)    Represents “Not Rated.”
Amounts Due (To) From Reinsurers	Amounts Due (To) From Reinsurers
	As of March 31, 2015
		Assumed				Ceded			Assumed			Ceded
		Premium, net				Premium, net			Expected			Expected
		of Commissions				of Commissions			Loss and LAE			Loss and LAE
		(in millions)
	American Overseas Reinsurance Company Limited (f/k/a Ram Re)	$	—			$	(7	)	$	—		$	10
	Tokio Marine & Nichido Fire Insurance Co., Ltd.	—				(12		)	—			45
	Radian Asset	—				(12		)	—			18
	Syncora Guarantee Inc.	—				(27		)	—			4
	Mitsui Sumitomo Insurance Co. Ltd.	—				(3		)	—			14
	Swiss Reinsurance Co.	—				(2		)	—			6
	Ambac	43				—			(18		)	—
	Ambac Assurance Corp. Segregated Account	12				—			(77		)	—
	CIFG Assurance North America Inc.	—				—			(7		)	—
	MBIA	6				—			(10		)	—
	NPFGC	6				—			(7		)	—
	Financial Guaranty Insurance Co.	4				—			(2		)	—
	Other	2				(4		)	—			—
	Total	$	73			$	(67	)	$	(121	)	$	97

LongTerm_Debt_and_Credit_Facil1

Long-Term Debt and Credit Facilities (Tables)	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Principal and Carrying Amounts of Debt	Principal and Carrying Amounts of Debt
		As of March 31, 2015				As of December 31, 2014
		Principal		Carrying		Principal		Carrying
				Value				Value
		(in millions)
	AGUS:
	7.0% Senior Notes	$	200	$	198	$	200	$	198
	5.0% Senior Notes	500		499		500		499
	Series A Enhanced Junior Subordinated Debentures	150		150		150		150
	Total AGUS	850		847		850		847
	AGMH:
	67/8% QUIBS	100		68		100		68
	6.25% Notes	230		139		230		139
	5.60% Notes	100		55		100		55
	Junior Subordinated Debentures	300		177		300		175
	Total AGMH	730		439		730		437
	AGM:
	Notes Payable	15		18		16		19
	Total AGM	15		18		16		19
	Total	$	1,595	$	1,304	$	1,596	$	1,303

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted earnings per share	Computation of Earnings Per Share
		First Quarter
		2015		2014
		(in millions, except per share amounts)
	Basic earnings per share ("EPS"):
	Net income (loss) attributable to AGL	$	201	$	42
	Less: Distributed and undistributed income (loss) available to nonvested shareholders	0		0
	Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	$	201	$	42
	Basic shares	155.8		182.1
	Basic EPS	$	1.29	$	0.23
	Diluted EPS:
	Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	$	201	$	42
	Plus: Re-allocation of undistributed income (loss) available to nonvested shareholders of AGL and subsidiaries	0		—
	Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, diluted	$	201	$	42
	Basic shares	155.8		182.1
	Effect of dilutive securities:
	Options and restricted stock awards	1		1
	Diluted shares	156.8		183.1
	Diluted EPS	$	1.28	$	0.23
	Potentially dilutive securities excluded from computation of EPS because of antidilutive effect	0.7		1.5
Schedule of antidilutive securities excluded from computation of earnings per share	Computation of Earnings Per Share
		First Quarter
		2015		2014
		(in millions, except per share amounts)
	Basic earnings per share ("EPS"):
	Net income (loss) attributable to AGL	$	201	$	42
	Less: Distributed and undistributed income (loss) available to nonvested shareholders	0		0
	Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	$	201	$	42
	Basic shares	155.8		182.1
	Basic EPS	$	1.29	$	0.23
	Diluted EPS:
	Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	$	201	$	42
	Plus: Re-allocation of undistributed income (loss) available to nonvested shareholders of AGL and subsidiaries	0		—
	Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, diluted	$	201	$	42
	Basic shares	155.8		182.1
	Effect of dilutive securities:
	Options and restricted stock awards	1		1
	Diluted shares	156.8		183.1
	Diluted EPS	$	1.28	$	0.23
	Potentially dilutive securities excluded from computation of EPS because of antidilutive effect	0.7		1.5

Shareholders_Equity_Tables

Shareholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Changes in Accumulated Other Comprehensive Income by Component	Changes in Accumulated Other Comprehensive Income by Component
	First Quarter 2015
		Net Unrealized			Net Unrealized			Cumulative			Cash Flow Hedge			Total Accumulated
		Gains (Losses) on			Gains (Losses) on			Translation						Other
		Investments with no Other-Than-Temporary Impairment			Investments with Other-Than-Temporary Impairment			Adjustment						Comprehensive
														Income
		(in millions)
	Balance, December 31, 2014	$	367		$	4		$	(10	)	$	9		$	370
	Other comprehensive income (loss) before reclassifications	18			(2		)	(5		)	—			11
	Amounts reclassified from AOCI to:
	Net realized investment gains (losses)	(20		)	4			—			—			(16		)
	Interest expense	—			—			—			(1		)	(1		)
	Total before tax	(20		)	4			—			(1		)	(17		)
	Tax (provision) benefit	7			(1		)	—			0			6
	Total amount reclassified from AOCI, net of tax	(13		)	3			—			(1		)	(11		)
	Net current period other comprehensive income (loss)	5			1			(5		)	(1		)	0
	Balance, March 31, 2015	$	372		$	5		$	(15	)	$	8		$	370
	Changes in Accumulated Other Comprehensive Income by Component
	First Quarter 2014
		Net Unrealized			Net Unrealized			Cumulative			Cash Flow Hedge			Total Accumulated
		Gains (Losses) on			Gains (Losses) on			Translation						Other
		Investments with no Other-Than-Temporary Impairment			Investments with Other-Than-Temporary Impairment			Adjustment						Comprehensive
														Income
		(in millions)
	Balance, December 31, 2013	$	178		$	(24	)	$	(3	)	$	9		$	160
	Other comprehensive income (loss) before reclassifications	94			8			1			—			103
	Amounts reclassified from AOCI to:
	Net realized investment gains (losses)	(2		)	5			—			—			3
	Interest expense	—			—			—			0			0
	Total before tax	(2		)	5			—			0			3
	Tax (provision) benefit	1			(2		)	—			(1		)	(2		)
	Total amount reclassified from AOCI, net of tax	(1		)	3			—			(1		)	1
	Net current period other comprehensive income (loss)	93			11			1			(1		)	104
	Balance, March 31, 2014	$	271		$	(13	)	$	(2	)	$	8		$	264
Schedule of Share Repurchases	Share Repurchases
	Period		Number of Shares Repurchased		Total Payments(in millions)			Average Price Paid Per Share
	2013		12,512,759		$	264		$	21.12
	2014 (January 1 - March 31)		1,350,443		35			25.92
	2014 (April 1 - June 30)		7,051,842		177			25.14
	2014 (July 1 - September 30)		9,623,309		226			23.47
	2014 (October 1 - December 31)		6,388,187		152			23.83
	Total 2014		24,413,781		590			24.17
	2015 (January 1 - March 31)		5,860,291		152			25.87
	Total 2015 (through March 31)		5,860,291		152			25.87
	2015 (April 1 - through May 8)		2,058,927		56			27.36
	Total 2015		7,919,218		208			26.26
	Cumulative repurchases since the beginning of 2013		44,845,758		$	1,062		$	23.69

Subsidiary_Information_Tables

Subsidiary Information (Tables)	3 Months Ended
	Mar. 31, 2015
Subsidiary Information [abstract]
Condensed Consolidating Balance Sheet	CONDENSED CONSOLIDATING BALANCE SHEET
	AS OF MARCH 31, 2015
	(in millions)
		Assured			AGUS			AGMH			Other			Consolidating			Assured
		Guaranty Ltd.			(Issuer)			(Issuer)			Entities			Adjustments			Guaranty Ltd.
		(Parent)															(Consolidated)
	ASSETS
	Total investment portfolio and cash	$	47		$	82		$	23		$	11,347		$	(300	)	$	11,199
	Investment in subsidiaries	5,722			5,087			3,955			350			(15,114		)	—
	Premiums receivable, net of commissions payable	—			—			—			830			(130		)	700
	Ceded unearned premium reserve	—			—			—			1,430			(1,065		)	365
	Deferred acquisition costs	—			—			—			184			(64		)	120
	Reinsurance recoverable on unpaid losses	—			—			—			344			(267		)	77
	Credit derivative assets	—			—			—			262			(185		)	77
	Deferred tax asset, net	—			56			—			251			(89		)	218
	Intercompany receivable	—			200			—			90			(290		)	—
	Financial guaranty variable interest entities’ assets, at fair value	—			—			—			1,499			—			1,499
	Other	21			79			31			522			(231		)	422
	TOTAL ASSETS	$	5,790		$	5,504		$	4,009		$	17,109		$	(17,735	)	$	14,677
	LIABILITIES AND SHAREHOLDERS’ EQUITY
	Unearned premium reserves	$	—		$	—		$	—		$	5,173		$	(1,046	)	$	4,127
	Loss and LAE reserve	—			—			—			1,062			(275		)	787
	Long-term debt	—			847			439			18			—			1,304
	Intercompany payable	—			90			—			500			(590		)	—
	Credit derivative liabilities	—			—			—			1,044			(185		)	859
	Deferred tax liabilities, net	—			—			93			—			(93		)	—
	Financial guaranty variable interest entities’ liabilities, at fair value	—			—			—			1,423			—			1,423
	Other	4			23			22			702			(360		)	391
	TOTAL LIABILITIES	4			960			554			9,922			(2,549		)	8,891
	TOTAL SHAREHOLDERS’ EQUITY ATTRIBUTABLE TO ASSURED GUARANTY LTD.	5,786			4,544			3,455			6,837			(14,836		)	5,786
	Noncontrolling interest	—			—			—			350			(350		)	—
	TOTAL SHAREHOLDERS' EQUITY	5,786			4,544			3,455			7,187			(15,186		)	5,786
	TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$	5,790		$	5,504		$	4,009		$	17,109		$	(17,735	)	$	14,677
	CONDENSED CONSOLIDATING BALANCE SHEET
	AS OF DECEMBER 31, 2014
	(in millions)
		Assured			AGUS			AGMH			Other			Consolidating			Assured
		Guaranty Ltd.			(Issuer)			(Issuer)			Entities			Adjustments			Guaranty Ltd.
		(Parent)															(Consolidated)
	ASSETS
	Total investment portfolio and cash	$	126		$	204		$	47		$	11,382		$	(300	)	$	11,459
	Investment in subsidiaries	5,612			5,072			3,965			339			(14,988		)	—
	Premiums receivable, net of commissions payable	—			—			—			864			(135		)	729
	Ceded unearned premium reserve	—			—			—			1,469			(1,088		)	381
	Deferred acquisition costs	—			—			—			186			(65		)	121
	Reinsurance recoverable on unpaid losses	—			—			—			338			(260		)	78
	Credit derivative assets	—			—			—			277			(209		)	68
	Deferred tax asset, net	—			54			—			295			(89		)	260
	Intercompany receivable	—			—			—			90			(90		)	—
	Financial guaranty variable interest entities’ assets, at fair value	—			—			—			1,402			—			1,402
	Other	27			77			27			538			(242		)	427
	TOTAL ASSETS	$	5,765		$	5,407		$	4,039		$	17,180		$	(17,466	)	$	14,925
	LIABILITIES AND SHAREHOLDERS’ EQUITY
	Unearned premium reserves	$	—		$	—		$	—		$	5,328		$	(1,067	)	$	4,261
	Loss and LAE reserve	—			—			—			1,066			(267		)	799
	Long-term debt	—			847			437			19			—			1,303
	Intercompany payable	—			90			—			300			(390		)	—
	Credit derivative liabilities	—			—			—			1,172			(209		)	963
	Deferred tax liabilities, net	—			—			94			—			(94		)	—
	Financial guaranty variable interest entities’ liabilities, at fair value	—			—			—			1,419			—			1,419
	Other	7			9			16			764			(374		)	422
	TOTAL LIABILITIES	7			946			547			10,068			(2,401		)	9,167
	TOTAL SHAREHOLDERS’ EQUITY ATTRIBUTABLE TO ASSURED GUARANTY LTD.	5,758			4,461			3,492			6,773			(14,726		)	5,758
	Noncontrolling interest	—			—			—			339			(339		)	—
TOTAL SHAREHOLDERS’ EQUITY	5,758			4,461			3,492			7,112			(15,065		)	5,758
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$	5,765		$	5,407		$	4,039		$	17,180		$	(17,466	)	$	14,925
Condensed Consolidating Statement of Operations and Comprehensive Income	CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS
	AND COMPREHENSIVE INCOME
	FOR THE THREE MONTHS ENDED MARCH 31, 2015
	(in millions)
		Assured			AGUS			AGMH			Other			Consolidating			Assured
		Guaranty Ltd.			(Issuer)			(Issuer)			Entities			Adjustments			Guaranty Ltd.
		(Parent)															(Consolidated)
	REVENUES
	Net earned premiums	$	—		$	—		$	—		$	140		$	2		$	142
	Net investment income	0			0			0			104			(3		)	101
	Net realized investment gains (losses)	0			0			0			19			(3		)	16
	Net change in fair value of credit derivatives:
	Realized gains (losses) and other settlements	—			—			—			21			0			21
	Net unrealized gains (losses)	—			—			—			103			—			103
	Net change in fair value of credit derivatives	—			—			—			124			0			124
	Other	—			—			—			(14		)	—			(14		)
	TOTAL REVENUES	0			0			—			373			(4		)	369
	EXPENSES
	Loss and LAE	—			—			—			18			0			18
	Amortization of deferred acquisition costs	—			—			—			6			(2		)	4
	Interest expense	—			13			13			4			(5		)	25
	Other operating expenses	8			0			0			48			0			56
	TOTAL EXPENSES	8			13			13			76			(7		)	103
	INCOME (LOSS) BEFORE INCOME TAXES AND EQUITY IN NET EARNINGS OF SUBSIDIARIES	(8		)	(13		)	(13		)	297			3			266
	Total (provision) benefit for income taxes	—			5			5			(72		)	(3		)	(65		)
	Equity in net earnings of subsidiaries	209			163			92			9			(473		)	—
	NET INCOME (LOSS)	$	201		$	155		$	84		$	234		$	(473	)	$	201
	Less: noncontrolling interest	—			—			—			9			(9		)	—
	NET INCOME (LOSS) ATTRIBUTABLE TO ASSURED GUARANTY LTD.	$	201		$	155		$	84		$	225		$	(464	)	$	201
	COMPREHENSIVE INCOME (LOSS)	$	201		$	134		$	80		$	233		$	(447	)	$	201
	CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS
	AND COMPREHENSIVE INCOME
	FOR THE THREE MONTHS ENDED MARCH 31, 2014
	(in millions)
		Assured			AGUS			AGMH			Other			Consolidating			Assured
		Guaranty Ltd.			(Issuer)			(Issuer)			Entities			Adjustments			Guaranty Ltd.
		(Parent)															(Consolidated)
	REVENUES
	Net earned premiums	$	—		$	—		$	—		$	131		$	1		$	132
	Net investment income	0			0			0			105			(2		)	103
	Net realized investment gains (losses)	0			—			0			4			(2		)	2
	Net change in fair value of credit derivatives:
	Realized gains (losses) and other settlements	—			—			—			19			0			19
	Net unrealized gains (losses)	—			—			—			(230		)	—			(230		)
	Net change in fair value of credit derivatives	—			—			—			(211		)	0			(211		)
	Other	—			—			—			169			—			169
	TOTAL REVENUES	0			0			0			198			(3		)	195
	EXPENSES
	Loss and LAE	—			—			—			39			2			41
	Amortization of deferred acquisition costs	—			—			—			6			(1		)	5
	Interest expense	—			7			13			5			(5		)	20
	Other operating expenses	8			0			0			53			(1		)	60
	TOTAL EXPENSES	8			7			13			103			(5		)	126
	INCOME (LOSS) BEFORE INCOME TAXES AND EQUITY IN NET EARNINGS OF SUBSIDIARIES	(8		)	(7		)	(13		)	95			2			69
	Total (provision) benefit for income taxes	—			2			5			(33		)	(1		)	(27		)
	Equity in net earnings of subsidiaries	50			87			169			8			(314		)	—
	NET INCOME (LOSS)	$	42		$	82		$	161		$	70		$	(313	)	$	42
	Less: noncontrolling interest	—			—			—			8			(8		)	—
	NET INCOME (LOSS) ATTRIBUTABLE TO ASSURED GUARANTY LTD.	$	42		$	82		$	161		$	62		$	(305	)	$	42
	COMPREHENSIVE INCOME (LOSS)	$	146		$	165		$	212		$	258		$	(635	)	$	146
Condensed Consolidating Statement of Cash Flows	CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
	FOR THE THREE MONTHS ENDED MARCH 31, 2015
	(in millions)
		Assured			AGUS			AGMH			Other			Consolidating			Assured
		Guaranty Ltd.			(Issuer)			(Issuer)			Entities			Adjustments			Guaranty Ltd.
		(Parent)															(Consolidated)
	Net cash flows provided by (used in) operating activities	$	97		$	127		$	59		$	34		$	(294	)	$	23
	Cash flows from investing activities
	Fixed-maturity securities:
	Purchases	—			(46		)	(6		)	(396		)	—			(448		)
	Sales	—			122			11			708			—			841
	Maturities	—			4			—			151			—			155
	Sales (purchases) of short-term investments, net	79			43			19			279			—			420
	Net proceeds from financial guaranty variable entities’ assets	—			—			—			30			—			30
	Intercompany debt	—			(200		)	—			—			200			—
	Investment in subsidiary	—			—			25			—			(25		)	—
	Other	—			—			—			3			—			3
	Net cash flows provided by (used in) investing activities	79			(77		)	49			775			175			1,001
	Cash flows from financing activities
	Return of capital	—			—			—			(25		)	25			—
	Dividends paid	(19		)	(50		)	(108		)	(136		)	294			(19		)
	Repurchases of common stock	(152		)	—			—			—			—			(152		)
	Share activity under option and incentive plans	(5		)	—			—			—			—			(5		)
	Net paydowns of financial guaranty variable entities’ liabilities	—			—			—			(39		)	—			(39		)
	Payment of long-term debt	—			—			—			(1		)	—			(1		)
	Intercompany debt	—			—			—			200			(200		)	—
	Other	—			—			—			4			—			4
	Net cash flows provided by (used in) financing activities	(176		)	(50		)	(108		)	3			119			(212		)
	Effect of exchange rate changes	—			—			—			(2		)	—			(2		)
	Increase (decrease) in cash	—			—			—			810			—			810
	Cash at beginning of period	0			0			4			71			—			75
	Cash at end of period	$	0		$	0		$	4		$	881		$	—		$	885
	CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
	FOR THE THREE MONTHS ENDED MARCH 31, 2014
	(in millions)
		Assured			AGUS			AGMH			Other			Consolidating			Assured
		Guaranty Ltd.			(Issuer)			(Issuer)			Entities			Adjustments			Guaranty Ltd.
		(Parent)															(Consolidated)
	Net cash flows provided by (used in) operating activities	$	58		$	0		$	(6	)	$	111		$	(62	)	$	101
	Cash flows from investing activities
	Fixed-maturity securities:
	Purchases	—			(1		)	(3		)	(513		)	—			(517		)
	Sales	—			—			—			155			—			155
	Maturities	—			—			—			148			—			148
	Sales (purchases) of short-term investments, net	(3		)	—			(16		)	203			—			184
	Net proceeds from financial guaranty variable entities’ assets	—			—			—			286			—			286
	Intercompany debt	—			—			—			—			—			—
	Investment in subsidiary	—			—			25			—			(25		)	—
	Other	—			—			—			19			—			19
	Net cash flows provided by (used in) investing activities	(3		)	(1		)	6			298			(25		)	275
	Cash flows from financing activities
	Return of capital	—			—			—			(25		)	25			—
	Dividends paid	(20		)	—			—			(62		)	62			(20		)
	Repurchases of common stock	(35		)	—			—			—			—			(35		)
	Share activity under option and incentive plans	0			—			—			—			—			0
	Net paydowns of financial guaranty variable entities’ liabilities	—			—			—			(281		)	—			(281		)
	Payment of long-term debt	—			—			—			(6		)	—			(6		)
	Intercompany debt	—			—			—			—			—			—
	Net cash flows provided by (used in) financing activities	(55		)	—			—			(374		)	87			(342		)
	Effect of exchange rate changes	—			—			—			1			—			1
	Increase (decrease) in cash	—			(1		)	—			36			—			35
	Cash at beginning of period	0			67			0			117			—			184
	Cash at end of period	$	0		$	66		$	0		$	153		$	—		$	219

Business_and_Basis_of_Presenta2

Business and Basis of Presentation (Details) (USD $)	3 Months Ended	0 Months Ended
	Mar. 31, 2015	Apr. 01, 2015
	Company
Business Acquisition [Line Items]
Number of holding companies having public debt outstanding	2
Debt issuance cost	$6,000,000
Radian [Member]
Business Acquisition [Line Items]
Qualified statutory capital	1,300,000,000
Subsequent Event [Member] | Radian [Member]
Business Acquisition [Line Items]
Expected payments to acquire business in first half of 2015		804,500,000
Net par amount outstanding		$13,600,000,000

Outstanding_Exposure_Debt_Serv

Outstanding Exposure - Debt Service Outstanding (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Schedule of Insured Financial Obligations [Line Items]
Gross Debt Service Outstanding	$619,932	$646,722
Net Debt Service Outstanding	584,659	609,622
Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Gross Debt Service Outstanding	565,386	587,245
Net Debt Service Outstanding	533,359	553,612
Structured Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Gross Debt Service Outstanding	54,546	59,477
Net Debt Service Outstanding	$51,300	$56,010

Outstanding_Exposure_Financial

Outstanding Exposure - Financial Guaranty Portfolio by Internal Rating (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	$389,099,000,000	[1]	$403,729,000,000	[2]
% of total net par outstanding	100.00%	[1]	100.00%	[2]
Loss mitigation bonds	1,300,000,000		1,300,000,000
AAA [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	26,749,000,000		30,143,000,000
% of total net par outstanding	6.90%		7.50%
AA [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	97,908,000,000		101,965,000,000
% of total net par outstanding	25.20%		25.30%
A [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	180,992,000,000		186,875,000,000
% of total net par outstanding	46.40%		46.30%
BBB [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	65,590,000,000		66,499,000,000
% of total net par outstanding	16.90%		16.40%
BIG [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	17,860,000,000		18,247,000,000
% of total net par outstanding	4.60%		4.50%
Public Finance [Member] | United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	313,444,000,000	[1]	322,123,000,000	[2]
% of total net par outstanding	100.00%	[1]	100.00%	[2]
Public Finance [Member] | Non United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	29,619,000,000	[1]	31,359,000,000	[2]
% of total net par outstanding	100.00%	[1]	100.00%	[2]
Public Finance [Member] | AAA [Member] | United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	3,563,000,000		4,082,000,000
% of total net par outstanding	1.10%		1.30%
Public Finance [Member] | AAA [Member] | Non United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	613,000,000		615,000,000
% of total net par outstanding	2.10%		2.00%
Public Finance [Member] | AA [Member] | United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	86,521,000,000		90,464,000,000
% of total net par outstanding	27.60%		28.10%
Public Finance [Member] | AA [Member] | Non United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	2,650,000,000		2,785,000,000
% of total net par outstanding	9.00%		8.90%
Public Finance [Member] | A [Member] | United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	171,308,000,000		176,298,000,000
% of total net par outstanding	54.70%		54.70%
Public Finance [Member] | A [Member] | Non United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	7,091,000,000		7,192,000,000
% of total net par outstanding	23.90%		22.90%
Public Finance [Member] | BBB [Member] | United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	44,110,000,000		43,429,000,000
% of total net par outstanding	14.10%		13.50%
Public Finance [Member] | BBB [Member] | Non United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	17,891,000,000		19,363,000,000
% of total net par outstanding	60.40%		61.70%
Public Finance [Member] | BIG [Member] | United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	7,942,000,000		7,850,000,000
% of total net par outstanding	2.50%		2.40%
Public Finance [Member] | BIG [Member] | Non United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	1,374,000,000		1,404,000,000
% of total net par outstanding	4.60%		4.50%
Structured Finance [Member] | United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	38,430,000,000	[1]	41,171,000,000	[2]
% of total net par outstanding	100.00%	[1]	100.00%	[2]
Structured Finance [Member] | Non United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	7,606,000,000	[1]	9,076,000,000	[2]
% of total net par outstanding	100.00%	[1]	100.00%	[2]
Structured Finance [Member] | AAA [Member] | United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	18,176,000,000		20,037,000,000
% of total net par outstanding	47.30%		48.70%
Structured Finance [Member] | AAA [Member] | Non United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	4,397,000,000		5,409,000,000
% of total net par outstanding	57.80%		59.60%
Structured Finance [Member] | AA [Member] | United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	8,360,000,000		8,213,000,000
% of total net par outstanding	21.70%		19.90%
Structured Finance [Member] | AA [Member] | Non United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	377,000,000		503,000,000
% of total net par outstanding	5.00%		5.50%
Structured Finance [Member] | A [Member] | United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	2,228,000,000		2,940,000,000
% of total net par outstanding	5.80%		7.10%
Structured Finance [Member] | A [Member] | Non United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	365,000,000		445,000,000
% of total net par outstanding	4.70%		4.90%
Structured Finance [Member] | BBB [Member] | United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	1,843,000,000		1,795,000,000
% of total net par outstanding	4.80%		4.40%
Structured Finance [Member] | BBB [Member] | Non United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	1,746,000,000		1,912,000,000
% of total net par outstanding	23.00%		21.10%
Structured Finance [Member] | BIG [Member] | United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	7,823,000,000		8,186,000,000
% of total net par outstanding	20.40%		19.90%
Structured Finance [Member] | BIG [Member] | Non United States [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	$721,000,000		$807,000,000
% of total net par outstanding	9.50%		8.90%
[1]	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of March 31, 2015, which are primarily in the BIG category.
[2]	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of December 31, 2014, which are primarily in the BIG category.

Outstanding_Exposure_Component

Outstanding Exposure - Components of BIG Net Par Outstanding (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	$389,099	[1]	$403,729	[2]
Triple-X Life Insurance Transaction [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	3,133		3,133
Trust Preferred Securities (TruPS) [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	4,075		4,326
Other structured finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	29,750		33,371
BIG [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	17,860		18,247
BIG [Member] | Triple-X Life Insurance Transaction [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	598		598
BIG [Member] | Trust Preferred Securities (TruPS) [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	1,155		1,333
BIG [Member] | Other structured finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	1,319		1,419
BIG [Member] | BIG 1 [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	11,338		11,865
BIG [Member] | BIG 1 [Member] | Triple-X Life Insurance Transaction [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	0		0
BIG [Member] | BIG 1 [Member] | Trust Preferred Securities (TruPS) [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	828		997
BIG [Member] | BIG 1 [Member] | Other structured finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	927		1,021
BIG [Member] | BIG 2 [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	3,029		2,689
BIG [Member] | BIG 2 [Member] | Triple-X Life Insurance Transaction [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	0		0
BIG [Member] | BIG 2 [Member] | Trust Preferred Securities (TruPS) [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	0		0
BIG [Member] | BIG 2 [Member] | Other structured finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	237		240
BIG [Member] | BIG 3 [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	3,493		3,693
BIG [Member] | BIG 3 [Member] | Triple-X Life Insurance Transaction [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	598		598
BIG [Member] | BIG 3 [Member] | Trust Preferred Securities (TruPS) [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	327		336
BIG [Member] | BIG 3 [Member] | Other structured finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	155		158
United States [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	313,444	[1]	322,123	[2]
United States [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	9,078		9,417
United States [Member] | BIG [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	7,942		7,850
United States [Member] | BIG [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	5,472		5,643
United States [Member] | BIG [Member] | BIG 1 [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	6,669		6,577
United States [Member] | BIG [Member] | BIG 1 [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	2,051		1,868
United States [Member] | BIG [Member] | BIG 2 [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	1,156		1,156
United States [Member] | BIG [Member] | BIG 2 [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	1,125		1,291
United States [Member] | BIG [Member] | BIG 3 [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	117		117
United States [Member] | BIG [Member] | BIG 3 [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	2,296		2,484
Non United States [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	29,619	[1]	31,359	[2]
Non United States [Member] | BIG [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	1,374		1,404
Non United States [Member] | BIG [Member] | BIG 1 [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	863		1,402
Non United States [Member] | BIG [Member] | BIG 2 [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	511		2
Non United States [Member] | BIG [Member] | BIG 3 [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	0		0
First Lien [Member] | United States [Member] | Prime [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	454		471
First Lien [Member] | United States [Member] | Alt-A [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	2,449		2,532
First Lien [Member] | United States [Member] | Option ARM [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	374		407
First Lien [Member] | United States [Member] | Subprime [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	3,935		4,051
First Lien [Member] | United States [Member] | BIG [Member] | Prime [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	349		353
First Lien [Member] | United States [Member] | BIG [Member] | Alt-A [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	1,778		1,841
First Lien [Member] | United States [Member] | BIG [Member] | Option ARM [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	170		183
First Lien [Member] | United States [Member] | BIG [Member] | Subprime [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	1,539		1,575
First Lien [Member] | United States [Member] | BIG [Member] | BIG 1 [Member] | Prime [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	49		68
First Lien [Member] | United States [Member] | BIG [Member] | BIG 1 [Member] | Alt-A [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	579		585
First Lien [Member] | United States [Member] | BIG [Member] | BIG 1 [Member] | Option ARM [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	9		47
First Lien [Member] | United States [Member] | BIG [Member] | BIG 1 [Member] | Subprime [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	179		156
First Lien [Member] | United States [Member] | BIG [Member] | BIG 2 [Member] | Prime [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	59		33
First Lien [Member] | United States [Member] | BIG [Member] | BIG 2 [Member] | Alt-A [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	436		531
First Lien [Member] | United States [Member] | BIG [Member] | BIG 2 [Member] | Option ARM [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	53		18
First Lien [Member] | United States [Member] | BIG [Member] | BIG 2 [Member] | Subprime [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	529		654
First Lien [Member] | United States [Member] | BIG [Member] | BIG 3 [Member] | Prime [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	241		252
First Lien [Member] | United States [Member] | BIG [Member] | BIG 3 [Member] | Alt-A [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	763		725
First Lien [Member] | United States [Member] | BIG [Member] | BIG 3 [Member] | Option ARM [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	108		118
First Lien [Member] | United States [Member] | BIG [Member] | BIG 3 [Member] | Subprime [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	831		765
Second Lien [Member] | United States [Member] | Closed-end [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	212		218
Second Lien [Member] | United States [Member] | HELOCs [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	1,654		1,738
Second Lien [Member] | United States [Member] | BIG [Member] | Closed-end [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	132		134
Second Lien [Member] | United States [Member] | BIG [Member] | HELOCs [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	1,504		1,557
Second Lien [Member] | United States [Member] | BIG [Member] | BIG 1 [Member] | Closed-end [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	0		0
Second Lien [Member] | United States [Member] | BIG [Member] | BIG 1 [Member] | HELOCs [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	1,235		1,012
Second Lien [Member] | United States [Member] | BIG [Member] | BIG 2 [Member] | Closed-end [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	19		19
Second Lien [Member] | United States [Member] | BIG [Member] | BIG 2 [Member] | HELOCs [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	29		36
Second Lien [Member] | United States [Member] | BIG [Member] | BIG 3 [Member] | Closed-end [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	113		115
Second Lien [Member] | United States [Member] | BIG [Member] | BIG 3 [Member] | HELOCs [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	$240		$509
[1]	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of March 31, 2015, which are primarily in the BIG category.
[2]	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of December 31, 2014, which are primarily in the BIG category.

Outstanding_Exposure_BIG_Net_P

Outstanding Exposure - BIG Net Par Outstanding (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, Credit Derivative	$31,731		$34,996
Net Par Outstanding (excluding loss mitigation bonds)	389,099	[1]	403,729	[2]
BIG [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, Financial Guaranty Insurance	14,937	[3]	15,222	[3]
Net Par Outstanding, Credit Derivative	2,923		3,025
Net Par Outstanding (excluding loss mitigation bonds)	17,860		18,247
Number of Risks, Financial Guaranty Insurance	356	[3],[4]	358	[3],[4]
Number of Risks, Credit Derivative	55	[4]	56	[4]
Number of Risks	411	[4]	414	[4]
BIG [Member] | BIG 1 [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, Financial Guaranty Insurance	9,887	[3]	10,195	[3]
Net Par Outstanding, Credit Derivative	1,451		1,670
Net Par Outstanding (excluding loss mitigation bonds)	11,338		11,865
Number of Risks, Financial Guaranty Insurance	164	[3],[4]	164	[3],[4]
Number of Risks, Credit Derivative	18	[4]	18	[4]
Number of Risks	182	[4]	182	[4]
BIG [Member] | BIG 2 [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, Financial Guaranty Insurance	2,345	[3]	2,135	[3]
Net Par Outstanding, Credit Derivative	684		554
Net Par Outstanding (excluding loss mitigation bonds)	3,029		2,689
Number of Risks, Financial Guaranty Insurance	73	[3],[4]	75	[3],[4]
Number of Risks, Credit Derivative	12	[4]	14	[4]
Number of Risks	85	[4]	89	[4]
BIG [Member] | BIG 3 [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, Financial Guaranty Insurance	2,705	[3]	2,892	[3]
Net Par Outstanding, Credit Derivative	788		801
Net Par Outstanding (excluding loss mitigation bonds)	$3,493		$3,693
Number of Risks, Financial Guaranty Insurance	119	[3],[4]	119	[3],[4]
Number of Risks, Credit Derivative	25	[4]	24	[4]
Number of Risks	144	[4]	143	[4]
[1]	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of March 31, 2015, which are primarily in the BIG category.
[2]	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of December 31, 2014, which are primarily in the BIG category.
[3]	Includes net par outstanding for FG VIEs.
[4]	A risk represents the aggregate of the financial guaranty policies that share the same revenue source for purposes of making Debt Service payments.

Outstanding_Exposure_Puerto_Ri

Outstanding Exposure - Puerto Rico Gross Par and Gross Debt Service Outstanding (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Schedule of Insured Financial Obligations [Line Items]
Gross Debt Service Outstanding	$619,932		$646,722
Puerto Rico [Member]
Schedule of Insured Financial Obligations [Line Items]
Gross par outstanding	6,036		6,035
Gross Debt Service Outstanding	9,927		10,074
Subject to the Terms of the Recovery Act [Member] | Puerto Rico [Member]
Schedule of Insured Financial Obligations [Line Items]
Gross par outstanding	3,059	[1]	3,058	[1]
Gross Debt Service Outstanding	5,252	[1]	5,326	[1]
Not Subject to the Terms of the Recovery Act [Member] | Puerto Rico [Member]
Schedule of Insured Financial Obligations [Line Items]
Gross par outstanding	2,977		2,977
Gross Debt Service Outstanding	$4,675		$4,748
[1]	On February 6, 2015, the U.S. District Court for the District of Puerto Rico ruled that the Recovery Act is preempted by the Federal Bankruptcy Code and is therefore void. On February 19, 2015, the Commonwealth appealed the ruling to the U.S. Court of Appeals for the First Circuit.

Outstanding_Exposure_Puerto_Ri1

Outstanding Exposure - Puerto Rico Net Par Outstanding (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	$389,099	[1]	$403,729	[2]
Puerto Rico [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	4,940		4,939
Puerto Rico [Member] | Subject to the Terms of the Recovery Act [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	2,448		2,447
Puerto Rico [Member] | Subject to the Terms of the Recovery Act [Member] | PRHTA (Transportation revenue) [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	844		844
Puerto Rico [Member] | Subject to the Terms of the Recovery Act [Member] | PREPA [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	773		772
Puerto Rico [Member] | Subject to the Terms of the Recovery Act [Member] | Puerto Rico Aqueduct and Sewer Authority [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	384		384
Puerto Rico [Member] | Subject to the Terms of the Recovery Act [Member] | PRHTA (Highway revenue) [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	273		273
Puerto Rico [Member] | Subject to the Terms of the Recovery Act [Member] | Puerto Rico Convention Center District Authority [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	174		174
Puerto Rico [Member] | Not Subject to the Terms of the Recovery Act [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	2,492		2,492
Puerto Rico [Member] | Not Subject to the Terms of the Recovery Act [Member] | Commonwealth of Puerto Rico - General Obligation Bonds [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	1,672		1,672
Puerto Rico [Member] | Not Subject to the Terms of the Recovery Act [Member] | Puerto Rico Municipal Finance Agency [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	399		399
Puerto Rico [Member] | Not Subject to the Terms of the Recovery Act [Member] | Puerto Rico Sales Tax Financing Corporation [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	269		269
Puerto Rico [Member] | Not Subject to the Terms of the Recovery Act [Member] | Puerto Rico Public Buildings Authority [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	100		100
Puerto Rico [Member] | Not Subject to the Terms of the Recovery Act [Member] | GDB [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	33		33
Puerto Rico [Member] | Not Subject to the Terms of the Recovery Act [Member] | PRIFA [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	18		18
Puerto Rico [Member] | Not Subject to the Terms of the Recovery Act [Member] | University of Puerto Rico [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	$1		$1
[1]	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of March 31, 2015, which are primarily in the BIG category.
[2]	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of December 31, 2014, which are primarily in the BIG category.

Outstanding_Exposure_Amortizat

Outstanding Exposure - Amortization Schedule of Puerto Rico BIG Net Par Outstanding and BIG Net Debt Service Outstanding (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Estimated BIG Net Par Amortization [Abstract]
Net Par Outstanding (excluding loss mitigation bonds)	$389,099	[1]	$403,729	[2]
Estimated BIG Net Debt Service Amortization [Abstract]
Total	584,659		609,622
Puerto Rico [Member]
Estimated BIG Net Par Amortization [Abstract]
Net Par Outstanding (excluding loss mitigation bonds)	4,940		4,939
BIG [Member]
Estimated BIG Net Par Amortization [Abstract]
Net Par Outstanding (excluding loss mitigation bonds)	17,860		18,247
BIG [Member] | Puerto Rico [Member]
Estimated BIG Net Par Amortization [Abstract]
2015 (April 1 - June 30)	0
2015 (July 1 - September 30)	297
2015 (October 1 - December 31)	33
2016	267
2017	207
2018	157
2019	187
2020	255
2021	109
2022	110
2023	141
2024	160
2025-2029	916
2030-2034	827
2035-2039	669
2040-2044	90
2045-2047	246
Net Par Outstanding (excluding loss mitigation bonds)	4,671
Estimated BIG Net Debt Service Amortization [Abstract]
2015 (April 1 - June 30)	3
2015 (July 1 - September 30)	413
2015 (October 1 - December 31)	37
2016	487
2017	415
2018	353
2019	375
2020	434
2021	274
2022	269
2023	297
2024	309
2025-2029	1,517
2030-2034	1,238
2035-2039	829
2040-2044	159
2045-2047	272
Total	7,681
Subject to the Terms of the Recovery Act [Member] | Puerto Rico [Member]
Estimated BIG Net Par Amortization [Abstract]
Net Par Outstanding (excluding loss mitigation bonds)	2,448		2,447
Subject to the Terms of the Recovery Act [Member] | BIG [Member] | Puerto Rico [Member]
Estimated BIG Net Par Amortization [Abstract]
2015 (April 1 - June 30)	0
2015 (July 1 - September 30)	126
2015 (October 1 - December 31)	0
2016	84
2017	41
2018	48
2019	61
2020	73
2021	51
2022	43
2023	102
2024	82
2025-2029	576
2030-2034	440
2035-2039	397
2040-2044	78
2045-2047	246
Net Par Outstanding (excluding loss mitigation bonds)	2,448
Estimated BIG Net Debt Service Amortization [Abstract]
2015 (April 1 - June 30)	2
2015 (July 1 - September 30)	186
2015 (October 1 - December 31)	2
2016	200
2017	153
2018	158
2019	168
2020	176
2021	151
2022	140
2023	198
2024	173
2025-2029	951
2030-2034	696
2035-2039	525
2040-2044	146
2045-2047	272
Total	4,297
Not Subject to the Terms of the Recovery Act [Member] | Puerto Rico [Member]
Estimated BIG Net Par Amortization [Abstract]
Net Par Outstanding (excluding loss mitigation bonds)	2,492		2,492
Not Subject to the Terms of the Recovery Act [Member] | BIG [Member] | Puerto Rico [Member]
Estimated BIG Net Par Amortization [Abstract]
2015 (April 1 - June 30)	0
2015 (July 1 - September 30)	171
2015 (October 1 - December 31)	33
2016	183
2017	166
2018	109
2019	126
2020	182
2021	58
2022	67
2023	39
2024	78
2025-2029	340
2030-2034	387
2035-2039	272
2040-2044	12
2045-2047	0
Net Par Outstanding (excluding loss mitigation bonds)	2,223
Estimated BIG Net Debt Service Amortization [Abstract]
2015 (April 1 - June 30)	1
2015 (July 1 - September 30)	227
2015 (October 1 - December 31)	35
2016	287
2017	262
2018	195
2019	207
2020	258
2021	123
2022	129
2023	99
2024	136
2025-2029	566
2030-2034	542
2035-2039	304
2040-2044	13
2045-2047	0
Total	$3,384
[1]	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of March 31, 2015, which are primarily in the BIG category.
[2]	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of December 31, 2014, which are primarily in the BIG category.

Outstanding_Exposure_Net_Direc

Outstanding Exposure - Net Direct Economic Exposure to Selected European Countries (Details) (USD $)	Mar. 31, 2015
In Millions, unless otherwise specified
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	$2,106	[1]
BIG [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	803	[1]
Hungary [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	439	[1]
Hungary [Member] | BIG [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	370	[1]
Italy [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	1,234	[1]
Italy [Member] | BIG [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1]
Portugal [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	102	[1]
Portugal [Member] | BIG [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	102	[1]
Spain [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	331	[1]
Spain [Member] | BIG [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	331	[1]
Total Sovereign Exposure [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	1,488	[1]
Total Sovereign Exposure [Member] | Non-Infrastructure Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	1,081	[1],[2]
Total Sovereign Exposure [Member] | Infrastructure finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	407	[1]
Total Sovereign Exposure [Member] | Hungary [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	265	[1]
Total Sovereign Exposure [Member] | Hungary [Member] | Non-Infrastructure Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1],[2]
Total Sovereign Exposure [Member] | Hungary [Member] | Infrastructure finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	265	[1]
Total Sovereign Exposure [Member] | Italy [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	790	[1]
Total Sovereign Exposure [Member] | Italy [Member] | Non-Infrastructure Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	779	[1],[2]
Total Sovereign Exposure [Member] | Italy [Member] | Infrastructure finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	11	[1]
Total Sovereign Exposure [Member] | Portugal [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	102	[1]
Total Sovereign Exposure [Member] | Portugal [Member] | Non-Infrastructure Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	91	[1],[2]
Total Sovereign Exposure [Member] | Portugal [Member] | Infrastructure finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	11	[1]
Total Sovereign Exposure [Member] | Spain [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	331	[1]
Total Sovereign Exposure [Member] | Spain [Member] | Non-Infrastructure Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	211	[1],[2]
Total Non-sovereign Exposure [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	618	[1]
Total Non-sovereign Exposure [Member] | Regulated utilities [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	210	[1]
Total Non-sovereign Exposure [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	408	[1]
Total Non-sovereign Exposure [Member] | Hungary [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	174	[1]
Total Non-sovereign Exposure [Member] | Hungary [Member] | Regulated utilities [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1]
Total Non-sovereign Exposure [Member] | Italy [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	444	[1]
Total Non-sovereign Exposure [Member] | Italy [Member] | Regulated utilities [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	210	[1]
Total Non-sovereign Exposure [Member] | Italy [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	234	[1]
Total Non-sovereign Exposure [Member] | Portugal [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1]
Total Non-sovereign Exposure [Member] | Portugal [Member] | Regulated utilities [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1]
Total Non-sovereign Exposure [Member] | Portugal [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1]
Total Non-sovereign Exposure [Member] | Spain [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	0	[1]
Total Non-sovereign Exposure [Member] | Spain [Member] | RMBS [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Par Outstanding, European Exposure	$0	[1]
[1]	While the Company’s exposures are shown in U.S. dollars, the obligations the Company insures are in various currencies, primarily Euros. One of the residential mortgage-backed securities included in the table above includes residential mortgages in both Italy and Germany, and only the portion of the transaction equal to the portion of the original mortgage pool in Italian mortgages is shown in the table.
[2]	The exposure shown in the “Non-infrastructure public finance” category is from transactions backed by receivable payments from sub-sovereigns in Italy, Spain and Portugal. Sub-sovereign debt is debt issued by a governmental entity or government backed entity, or supported by such an entity, that is other than direct sovereign debt of the ultimate governing body of the country.

Outstanding_Exposure_Narrative

Outstanding Exposure - Narrative (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014		Aug. 14, 2014
Schedule of Insured Financial Obligations [Line Items]
Probability of paying more claims than being reimbursed (as a percent)	50.00%
Net Debt Service Outstanding	$584,659		$609,622
Indirect European exposure	10,000
Net par amount outstanding	389,099	[1]	403,729	[2]
Pooled corporate obligations [Member]
Schedule of Insured Financial Obligations [Line Items]
Indirect European exposure	483
Structured Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Debt Service Outstanding	51,300		56,010
Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Debt Service Outstanding	533,359		553,612
BIG [Member]
Schedule of Insured Financial Obligations [Line Items]
Maximum period of liquidity claims (in years)	1 year
Net par amount outstanding	17,860		18,247
United Kingdom and Ireland [Member] | Mortgage Loans on Real Estate [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Debt Service Outstanding	113		127
Select European Countries [Member]
Schedule of Insured Financial Obligations [Line Items]
Indirect European exposure	355
Greece [Member] | Pooled corporate obligations [Member]
Schedule of Insured Financial Obligations [Line Items]
Indirect European exposure	11
Puerto Rico [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	4,940		4,939
Percentage of outstanding bonds of PREPA					60.00%
Puerto Rico [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	4,900
Puerto Rico [Member] | BIG [Member]
Schedule of Insured Financial Obligations [Line Items]
Net Debt Service Outstanding	7,681
Net par amount outstanding	4,671
Puerto Rico [Member] | BIG [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Net par amount outstanding	4,700
Commitment to Provide Guarantees [Member] | Structured Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Outstanding commitments to provide guaranties	38
Commitment to Provide Guarantees [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Outstanding commitments to provide guaranties	410
Commitments due before expiration date	210
Other commitments, future minimum payments, Remainder of Fiscal Year	$75
Minimum [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Expiration date for insured financial obligation commitments	9-Apr-15
Minimum [Member] | BIG [Member]
Schedule of Insured Financial Obligations [Line Items]
Constant discount rate (as a percent)	4.50%
Maximum [Member] | Public Finance [Member]
Schedule of Insured Financial Obligations [Line Items]
Expiration date for insured financial obligation commitments	25-Feb-17
Maximum [Member] | BIG [Member]
Schedule of Insured Financial Obligations [Line Items]
Constant discount rate (as a percent)	5.00%
[1]	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of March 31, 2015, which are primarily in the BIG category.
[2]	Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of December 31, 2014, which are primarily in the BIG category.

Financial_Guaranty_Insurance_P2

Financial Guaranty Insurance Premiums - Net Earned Premiums (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Financial Guarantee Insurance Premiums [Line Items]
Net earned premiums	$142		$132
Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Financial Guarantee Insurance Premiums [Line Items]
Scheduled net earned premiums	96		107
Acceleration of net earned premiums	41		19
Accretion of discount on net premiums receivable	4		6
Financial guaranty insurance net earned premiums	141		132
Other	1		0
Net earned premiums	142	[1]	132	[1]
Variable Interest Entity, Primary Beneficiary [Member]
Financial Guarantee Insurance Premiums [Line Items]
Net earned premiums	$5		$17
[1]	Excludes $5 million and $17 million for First Quarter 2015 and 2014, respectively, related to consolidated FG VIEs.

Financial_Guaranty_Insurance_P3

Financial Guaranty Insurance Premiums - Components of Unearned Premium Reserve (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Financial Guarantee Insurance Premiums [Line Items]
Unearned premium reserve, gross	$4,127		$4,261
Unearned premium reserve, ceded	365		381
Total net unearned premium reserve related to FG VIE	125		125
Contra-paid related to FG and VIEs	41		42
Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Financial Guarantee Insurance Premiums [Line Items]
Deferred premium revenue, gross	4,039		4,167
Deferred premium revenue, ceded	370		387
Deferred premium revenue, net	3,669	[1]	3,780	[1]
Contra-paid, gross	88	[2]	94	[2]
Contra-paid, ceded	-5	[2]	-6	[2]
Contra-paid, net	93	[1],[2]	100	[1],[2]
Unearned premium reserve, gross	4,127		4,261
Unearned premium reserve, ceded	365		381
Unearned premium reserve, net	3,762	[1]	3,880	[1]
Financial Guarantee Insurance Product Line [Member]
Financial Guarantee Insurance Premiums [Line Items]
Contra-paid, net	93
Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Financial Guarantee Insurance Premiums [Line Items]
Deferred premium revenue, gross	4,038		4,167
Deferred premium revenue, ceded	370		387
Deferred premium revenue, net	3,668	[1],[3]	3,780	[1]
Other Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Financial Guarantee Insurance Premiums [Line Items]
Deferred premium revenue, gross	1		0
Deferred premium revenue, ceded	0		0
Deferred premium revenue, net	$1	[1]	$0	[1]
[1]	Excludes $125 million and $125 million of deferred premium revenue, and $41 million and $42 million of contra-paid related to FG VIEs as of March 31, 2015 and December 31, 2014, respectively.
[2]	See Note 6, "Financial Guaranty Insurance Losses– Insurance Contracts' Loss Information" for an explanation of "contra-paid".
[3]	Excludes scheduled net earned premiums on consolidated FG VIEs of $125 million

Financial_Guaranty_Insurance_P4

Financial Guaranty Insurance Premiums - Gross Premium Receivable Net of Commissions on Assumed Business Roll Forward (Details) (USD $)	3 Months Ended				12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014
Effects of Reinsurance [Line Items]
Non-financial guaranty line of business	$1
Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Gross Premium Receivable Net of Ceding Commissions [Roll Forward]
Beginning of period, December 31	729		876		876
Gross premium written, net of commissions on assumed business	36		33
Gross premiums received, net of commissions on assumed business	-36		-53
Changes in the expected term	-6		-3
Accretion of discount, net of commissions on assumed business	5		7
Foreign exchange translation	-25		2
Consolidation/deconsolidation of FG VIEs	-4		1
Other adjustments	0		0
End of period, March 31	699	[1]	863	[1]
Variable Interest Entity, Primary Beneficiary [Member]
Gross Premium Receivable Net of Ceding Commissions [Roll Forward]
End of period, March 31	$22		$18
Foreign Currency Concentration Risk [Member] | Premiums Receivable [Member]
Gross Premium Receivable Net of Ceding Commissions [Roll Forward]
Percentage of installment premiums denominated in currencies other than the U.S. dollar	49.00%				51.00%
[1]	Excludes $22 million and $18 million as of March 31, 2015 and March 31, 2014, respectively, related to consolidated FG VIEs.

Financial_Guaranty_Insurance_P5

Financial Guaranty Insurance Premiums - Expected Collections of Gross Premiums Receivable Net of Commissions on Assumed Business (Details) (USD $)	Mar. 31, 2015
In Millions, unless otherwise specified
Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Financial Guarantee Insurance Premiums [Line Items]
2015 (April 1 – June 30)	$23
2015 (July 1 – September 30)	24
2015 (October 1 – December 31)	19
2016	74
2017	67
2018	61
2019	57
2020-2024	238
2025-2029	154
2030-2034	108
After 2034	98
Total	923	[1]
Variable Interest Entity, Primary Beneficiary [Member]
Financial Guarantee Insurance Premiums [Line Items]
Cash collections on FG VIEs	$28
[1]	Excludes expected cash collections on FG VIEs of $28 million.

Financial_Guaranty_Insurance_P6

Financial Guaranty Insurance Premiums - Scheduled Net Earned Premiums Insurance Contracts (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Variable Interest Entity, Primary Beneficiary [Member]
Financial Guarantee Insurance Premiums [Line Items]
Deferred premium revenue, net	$125
Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Financial Guarantee Insurance Premiums [Line Items]
Deferred premium revenue, net	3,669	[1]	3,780	[1]
Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Financial Guarantee Insurance Premiums [Line Items]
2015 (April 1 – June 30)	91
2015 (July 1 – September 30)	89
2015 (October 1 – December 31)	86
2016	334
2017	294
2018	267
2019	244
2020-2024	955
2025-2029	610
2030-2034	373
After 2034	325
Deferred premium revenue, net	3,668	[1],[2]	3,780	[1]
Future accretion	198
Total future net earned premiums	$3,866
[1]	Excludes $125 million and $125 million of deferred premium revenue, and $41 million and $42 million of contra-paid related to FG VIEs as of March 31, 2015 and December 31, 2014, respectively.
[2]	Excludes scheduled net earned premiums on consolidated FG VIEs of $125 million

Financial_Guaranty_Insurance_P7

Financial Guaranty Insurance Premiums - Selected Information for Policies Paid in Installments (Details) (Policies Paid in Installments [Member], USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Policies Paid in Installments [Member]
Financial Guarantee Insurance Premiums [Line Items]
Premiums receivable, net of commission payable	$699	$729
Gross deferred premium revenue	$1,334	$1,370
Weighted-average risk-free rate used to discount premiums	3.40%	3.50%
Weighted-average period of premiums receivable (in years)	9 years 4 months 24 days	9 years 4 months 24 days

Expected_Loss_to_be_Paid_Net_E

Expected Loss to be Paid - Net Expected Recoveries from Breaches of R&W Rollforward (Details) (RMBS [Member], United States [Member], USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	$317		$712
R&W development and accretion of discount during period	-51		48
R&W recovered during period	-21		-39
Future net R&W benefit at the end of the period	245	[1]	721	[1]
First Lien [Member]
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	232		569
R&W development and accretion of discount during period	-50		39
R&W recovered during period	-20		-38
Future net R&W benefit at the end of the period	162	[1]	570	[1]
First Lien [Member] | Prime [Member]
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	2		4
R&W development and accretion of discount during period	-1		-1
R&W recovered during period	0		0
Future net R&W benefit at the end of the period	1	[1]	3	[1]
First Lien [Member] | Alt-A [Member]
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	106		274
R&W development and accretion of discount during period	-10		3
R&W recovered during period	-2		-8
Future net R&W benefit at the end of the period	94	[1]	269	[1]
First Lien [Member] | Option ARM [Member]
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	15		173
R&W development and accretion of discount during period	-20		9
R&W recovered during period	-15		-30
Future net R&W benefit at the end of the period	-20	[1]	152	[1]
First Lien [Member] | Subprime [Member]
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	109		118
R&W development and accretion of discount during period	-19		28
R&W recovered during period	-3		0
Future net R&W benefit at the end of the period	87	[1]	146	[1]
Second Lien [Member]
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	85		143
R&W development and accretion of discount during period	-1		9
R&W recovered during period	-1		-1
Future net R&W benefit at the end of the period	83	[1]	151	[1]
Second Lien [Member] | Closed-end [Member]
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	85		98
R&W development and accretion of discount during period	-1		-3
R&W recovered during period	-1		0
Future net R&W benefit at the end of the period	83	[1]	95	[1]
Second Lien [Member] | HELOCs [Member]
Estimated Benefit From Recoveries From Breaches of R and W Net of Reinsurance [Roll Forward]
Future net R&W benefit at the beginning of the period	0		45
R&W development and accretion of discount during period	0		12
R&W recovered during period	0		-1
Future net R&W benefit at the end of the period	$0	[1]	$56	[1]
[1]	See the section "Breaches of Representations and Warranties" below for eligible assets held in trust.

Expected_Loss_to_be_Paid_Net_E1

Expected Loss to be Paid - Net Expected Loss to be Paid After Net Expected Recoveries for Breaches of R&W Rollforward (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	$1,169	[1]	$982	[1]
Economic loss development after recoveries for R&W	-3		12
(Paid) Recovered Losses After Recoveries for R&W	-12	[2]	-10	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	1,154	[1]	984	[1]
Period after the end of the reporting period within which the ceded paid losses are typically settled (in days)	45 days
Loss and LAE Reserve paid	4		6
Expected LAE to be paid	13				16
Subtotal [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	1,173	[1]	985	[1]
Economic loss development after recoveries for R&W	-2		13
(Paid) Recovered Losses After Recoveries for R&W	-18	[2]	-10	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	1,153	[1]	988	[1]
Public Finance [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	348	[1]	321	[1]
Economic loss development after recoveries for R&W	6		23
(Paid) Recovered Losses After Recoveries for R&W	-2	[2]	-6	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	352	[1]	338	[1]
Public Finance [Member] | United States [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	303	[1]	264	[1]
Economic loss development after recoveries for R&W	9		23
(Paid) Recovered Losses After Recoveries for R&W	-2	[2]	-6	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	310	[1]	281	[1]
Public Finance [Member] | Non United States [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	45	[1]	57	[1]
Economic loss development after recoveries for R&W	-3		0
(Paid) Recovered Losses After Recoveries for R&W	0	[2]	0	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	42	[1]	57	[1]
RMBS [Member] | United States [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	584	[1]	493	[1]
Economic loss development after recoveries for R&W	4		-10
(Paid) Recovered Losses After Recoveries for R&W	-18	[2]	-3	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	570	[1]	480	[1]
RMBS [Member] | First Lien [Member] | United States [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	595	[1]	620	[1]
Economic loss development after recoveries for R&W	-2		-17
(Paid) Recovered Losses After Recoveries for R&W	-24	[2]	-10	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	569	[1]	593	[1]
RMBS [Member] | First Lien [Member] | Prime [Member] | United States [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	4	[1]	21	[1]
Economic loss development after recoveries for R&W	0		-3
(Paid) Recovered Losses After Recoveries for R&W	-1	[2]	0	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	3	[1]	18	[1]
RMBS [Member] | First Lien [Member] | Alt-A [Member] | United States [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	304	[1]	304	[1]
Economic loss development after recoveries for R&W	-5		8
(Paid) Recovered Losses After Recoveries for R&W	-10	[2]	-4	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	289	[1]	308	[1]
RMBS [Member] | First Lien [Member] | Option ARM [Member] | United States [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	-16	[1]	-9	[1]
Economic loss development after recoveries for R&W	4		-15
(Paid) Recovered Losses After Recoveries for R&W	-4	[2]	-4	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	-16	[1]	-28	[1]
RMBS [Member] | First Lien [Member] | Subprime [Member] | United States [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	303	[1]	304	[1]
Economic loss development after recoveries for R&W	-1		-7
(Paid) Recovered Losses After Recoveries for R&W	-9	[2]	-2	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	293	[1]	295	[1]
RMBS [Member] | Second Lien [Member] | United States [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	-11	[1]	-127	[1]
Economic loss development after recoveries for R&W	6		7
(Paid) Recovered Losses After Recoveries for R&W	6	[2]	7	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	1	[1]	-113	[1]
RMBS [Member] | Second Lien [Member] | Closed-end [Member] | United States [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	8	[1]	-11	[1]
Economic loss development after recoveries for R&W	1		5
(Paid) Recovered Losses After Recoveries for R&W	2	[2]	2	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	11	[1]	-4	[1]
RMBS [Member] | Second Lien [Member] | HELOCs [Member] | United States [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	-19	[1]	-116	[1]
Economic loss development after recoveries for R&W	5		2
(Paid) Recovered Losses After Recoveries for R&W	4	[2]	5	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	-10	[1]	-109	[1]
Triple-X Life Insurance Transaction [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	161	[1]	75	[1]
Economic loss development after recoveries for R&W	5		13
(Paid) Recovered Losses After Recoveries for R&W	-1	[2]	-1	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	165	[1]	87	[1]
Trust Preferred Securities (TruPS) [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	23	[1]	51	[1]
Economic loss development after recoveries for R&W	-9		-19	[3]
(Paid) Recovered Losses After Recoveries for R&W	0	[2]	0	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	14	[1]	32	[1]
Other structured finance [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	57	[1]	45	[1]
Economic loss development after recoveries for R&W	-8		6
(Paid) Recovered Losses After Recoveries for R&W	3	[2]	0	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	52	[1]	51	[1]
Structured Finance [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	825	[1]	664	[1]
Economic loss development after recoveries for R&W	-8		-10
(Paid) Recovered Losses After Recoveries for R&W	-16	[2]	-4	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	801	[1]	650	[1]
Other Insurance Product Line [Member]
Present Value of Net Expected Loss and Loss Adjustment Expenses to be Paid [Roll Forward]
Beginning of Period, Net Expected Loss to be Paid After Recoveries for R&W	-4	[1]	-3	[1]
Economic loss development after recoveries for R&W	-1		-1
(Paid) Recovered Losses After Recoveries for R&W	6	[2]	0	[2]
End of Period, Net Expected Loss to be Paid After Recoveries for R&W	$1	[1]	($4)	[1]
[1]	Includes expected LAE to be paid of $13 million as of March 31, 2015 and $16 million as of December 31, 2014.
[2]	Net of ceded paid losses, whether or not such amounts have been settled with reinsurers. Ceded paid losses are typically settled 45 days after the end of the reporting period. Such amounts are recorded in reinsurance recoverable on paid losses included in other assets.
[3]	Refer to Note 8, Financial Guaranty Contracts Accounted for as Credit Derivatives.

Expected_Loss_to_be_Paid_Net_E2

Expected Loss to be Paid - Net Expected Loss to be Paid and Net Economic Loss Development by Accounting Model (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014		Dec. 31, 2013
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	$1,154	[1]	$984	[1]	$1,169	[1]	$982	[1]
Economic loss development after recoveries for R&W	-3		12
Subtotal [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	1,153	[1]	988	[1]	1,173	[1]	985	[1]
Economic loss development after recoveries for R&W	-2		13
Public Finance [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	352	[1]	338	[1]	348	[1]	321	[1]
Economic loss development after recoveries for R&W	6		23
Public Finance [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	310	[1]	281	[1]	303	[1]	264	[1]
Economic loss development after recoveries for R&W	9		23
Public Finance [Member] | Non United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	42	[1]	57	[1]	45	[1]	57	[1]
Economic loss development after recoveries for R&W	-3		0
RMBS [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	570	[1]	480	[1]	584	[1]	493	[1]
Economic loss development after recoveries for R&W	4		-10
RMBS [Member] | First Lien [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	569	[1]	593	[1]	595	[1]	620	[1]
Economic loss development after recoveries for R&W	-2		-17
RMBS [Member] | First Lien [Member] | Prime [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	3	[1]	18	[1]	4	[1]	21	[1]
Economic loss development after recoveries for R&W	0		-3
RMBS [Member] | First Lien [Member] | Alt-A [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	289	[1]	308	[1]	304	[1]	304	[1]
Economic loss development after recoveries for R&W	-5		8
RMBS [Member] | First Lien [Member] | Option ARM [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	-16	[1]	-28	[1]	-16	[1]	-9	[1]
Economic loss development after recoveries for R&W	4		-15
RMBS [Member] | First Lien [Member] | Subprime [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	293	[1]	295	[1]	303	[1]	304	[1]
Economic loss development after recoveries for R&W	-1		-7
RMBS [Member] | Second Lien [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	1	[1]	-113	[1]	-11	[1]	-127	[1]
Economic loss development after recoveries for R&W	6		7
RMBS [Member] | Second Lien [Member] | Closed-end [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	11	[1]	-4	[1]	8	[1]	-11	[1]
Economic loss development after recoveries for R&W	1		5
RMBS [Member] | Second Lien [Member] | HELOCs [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	-10	[1]	-109	[1]	-19	[1]	-116	[1]
Economic loss development after recoveries for R&W	5		2
Triple-X Life Insurance Transaction [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	165	[1]	87	[1]	161	[1]	75	[1]
Economic loss development after recoveries for R&W	5		13
Trust Preferred Securities (TruPS) [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	14	[1]	32	[1]	23	[1]	51	[1]
Economic loss development after recoveries for R&W	-9		-19	[2]
Other structured finance [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	52	[1]	51	[1]	57	[1]	45	[1]
Economic loss development after recoveries for R&W	-8		6
Structured Finance [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	801	[1]	650	[1]	825	[1]	664	[1]
Economic loss development after recoveries for R&W	-8		-10
Other Insurance Product Line [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	1	[1]	-4	[1]	-4	[1]	-3	[1]
Economic loss development after recoveries for R&W	-1		-1
Financial Guarantee Accounted for as Insurance Contracts [Member] | Subtotal [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	989				989
Economic loss development after recoveries for R&W	12		-23
Financial Guarantee Accounted for as Insurance Contracts [Member] | Public Finance [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	352				348
Economic loss development after recoveries for R&W	6		23
Financial Guarantee Accounted for as Insurance Contracts [Member] | Public Finance [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	310				303
Economic loss development after recoveries for R&W	9		23
Financial Guarantee Accounted for as Insurance Contracts [Member] | Public Finance [Member] | Non United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	42				45
Economic loss development after recoveries for R&W	-3		0
Financial Guarantee Accounted for as Insurance Contracts [Member] | RMBS [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	382				385
Economic loss development after recoveries for R&W	8		-62
Financial Guarantee Accounted for as Insurance Contracts [Member] | RMBS [Member] | First Lien [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	421				438
Economic loss development after recoveries for R&W	0		-5
Financial Guarantee Accounted for as Insurance Contracts [Member] | RMBS [Member] | First Lien [Member] | Prime [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	3				2
Economic loss development after recoveries for R&W	1		0
Financial Guarantee Accounted for as Insurance Contracts [Member] | RMBS [Member] | First Lien [Member] | Alt-A [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	278				288
Economic loss development after recoveries for R&W	2		19
Financial Guarantee Accounted for as Insurance Contracts [Member] | RMBS [Member] | First Lien [Member] | Option ARM [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	-17				-15
Economic loss development after recoveries for R&W	1		-16
Financial Guarantee Accounted for as Insurance Contracts [Member] | RMBS [Member] | First Lien [Member] | Subprime [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	157				163
Economic loss development after recoveries for R&W	-4		-8
Financial Guarantee Accounted for as Insurance Contracts [Member] | RMBS [Member] | Second Lien [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	-39				-53
Economic loss development after recoveries for R&W	8		-57
Financial Guarantee Accounted for as Insurance Contracts [Member] | RMBS [Member] | Second Lien [Member] | Closed-end [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	-24				-27
Economic loss development after recoveries for R&W	1		-1
Financial Guarantee Accounted for as Insurance Contracts [Member] | RMBS [Member] | Second Lien [Member] | HELOCs [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	-15				-26
Economic loss development after recoveries for R&W	7		-56
Financial Guarantee Accounted for as Insurance Contracts [Member] | Triple-X Life Insurance Transaction [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	157				153
Economic loss development after recoveries for R&W	4		13
Financial Guarantee Accounted for as Insurance Contracts [Member] | Trust Preferred Securities (TruPS) [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	0				1
Economic loss development after recoveries for R&W	-1		-1
Financial Guarantee Accounted for as Insurance Contracts [Member] | Other structured finance [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	98				102
Economic loss development after recoveries for R&W	-5		4
Financial Guarantee Accounted for as Insurance Contracts [Member] | Structured Finance [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	637				641
Economic loss development after recoveries for R&W	6		-46
Financial Guaranty Variable Interest Entities [Member] | Subtotal [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	122	[3]			126	[3]
Economic loss development after recoveries for R&W	3	[3]	47	[3]
Financial Guaranty Variable Interest Entities [Member] | Public Finance [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	0				0	[3]
Economic loss development after recoveries for R&W	0	[3]	0	[3]
Financial Guaranty Variable Interest Entities [Member] | Public Finance [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	0	[3]			0	[3]
Economic loss development after recoveries for R&W	0	[3]	0	[3]
Financial Guaranty Variable Interest Entities [Member] | Public Finance [Member] | Non United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	0	[3]			0	[3]
Economic loss development after recoveries for R&W	0	[3]	0	[3]
Financial Guaranty Variable Interest Entities [Member] | RMBS [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	122	[3]			126	[3]
Economic loss development after recoveries for R&W	3	[3]	47	[3]
Financial Guaranty Variable Interest Entities [Member] | RMBS [Member] | First Lien [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	86	[3]			88	[3]
Economic loss development after recoveries for R&W	4	[3]	-13	[3]
Financial Guaranty Variable Interest Entities [Member] | RMBS [Member] | First Lien [Member] | Prime [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	0	[3]			0	[3]
Economic loss development after recoveries for R&W	0	[3]	0	[3]
Financial Guaranty Variable Interest Entities [Member] | RMBS [Member] | First Lien [Member] | Alt-A [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	17	[3]			17	[3]
Economic loss development after recoveries for R&W	0	[3]	-12	[3]
Financial Guaranty Variable Interest Entities [Member] | RMBS [Member] | First Lien [Member] | Option ARM [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	0	[3]			0	[3]
Economic loss development after recoveries for R&W	0	[3]	1	[3]
Financial Guaranty Variable Interest Entities [Member] | RMBS [Member] | First Lien [Member] | Subprime [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	69	[3]			71	[3]
Economic loss development after recoveries for R&W	4	[3]	-2	[3]
Financial Guaranty Variable Interest Entities [Member] | RMBS [Member] | Second Lien [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	36	[3]			38	[3]
Economic loss development after recoveries for R&W	-1	[3]	60	[3]
Financial Guaranty Variable Interest Entities [Member] | RMBS [Member] | Second Lien [Member] | Closed-end [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	31	[3]			31	[3]
Economic loss development after recoveries for R&W	1	[3]	2	[3]
Financial Guaranty Variable Interest Entities [Member] | RMBS [Member] | Second Lien [Member] | HELOCs [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	5	[3]			7	[3]
Economic loss development after recoveries for R&W	-2	[3]	58	[3]
Financial Guaranty Variable Interest Entities [Member] | Triple-X Life Insurance Transaction [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	0	[3]			0	[3]
Economic loss development after recoveries for R&W	0	[3]	0	[3]
Financial Guaranty Variable Interest Entities [Member] | Trust Preferred Securities (TruPS) [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	0	[3]			0	[3]
Economic loss development after recoveries for R&W	0	[3]	0	[3]
Financial Guaranty Variable Interest Entities [Member] | Other structured finance [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	0	[3]			0	[3]
Economic loss development after recoveries for R&W	0	[3]	0	[3]
Financial Guaranty Variable Interest Entities [Member] | Structured Finance [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	122	[3]			126	[3]
Economic loss development after recoveries for R&W	3	[3]	47	[3]
Financial Guarantee Accounted for as Credit Derivatives [Member] | Subtotal [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	42	[2]			58	[2]
Economic loss development after recoveries for R&W	-17	[2]	-11	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | Public Finance [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	0				0	[2]
Economic loss development after recoveries for R&W	0	[2]	0	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | Public Finance [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	0	[2]			0	[2]
Economic loss development after recoveries for R&W	0	[2]	0	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | Public Finance [Member] | Non United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	0	[2]			0	[2]
Economic loss development after recoveries for R&W	0	[2]	0	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | RMBS [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	66	[2]			73	[2]
Economic loss development after recoveries for R&W	-7	[2]	5	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | RMBS [Member] | First Lien [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	62	[2]			69	[2]
Economic loss development after recoveries for R&W	-6	[2]	1	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | RMBS [Member] | First Lien [Member] | Prime [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	0	[2]			2	[2]
Economic loss development after recoveries for R&W	-1	[2]	-3	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | RMBS [Member] | First Lien [Member] | Alt-A [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	-6	[2]			-1	[2]
Economic loss development after recoveries for R&W	-7	[2]	1	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | RMBS [Member] | First Lien [Member] | Option ARM [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	1	[2]			-1	[2]
Economic loss development after recoveries for R&W	3	[2]	0	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | RMBS [Member] | First Lien [Member] | Subprime [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	67	[2]			69	[2]
Economic loss development after recoveries for R&W	-1	[2]	3	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | RMBS [Member] | Second Lien [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	4	[2]			4	[2]
Economic loss development after recoveries for R&W	-1	[2]	4	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | RMBS [Member] | Second Lien [Member] | Closed-end [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	4	[2]			4	[2]
Economic loss development after recoveries for R&W	-1	[2]	4	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | RMBS [Member] | Second Lien [Member] | HELOCs [Member] | United States [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	0	[2]			0	[2]
Economic loss development after recoveries for R&W	0	[2]	0	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | Triple-X Life Insurance Transaction [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	8	[2]			8	[2]
Economic loss development after recoveries for R&W	1	[2]	0	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | Trust Preferred Securities (TruPS) [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	14	[2]			22	[2]
Economic loss development after recoveries for R&W	-8	[2]	-18	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | Other structured finance [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	-46	[2]			-45	[2]
Economic loss development after recoveries for R&W	-3	[2]	2	[2]
Financial Guarantee Accounted for as Credit Derivatives [Member] | Structured Finance [Member]
Schedule of Expected Losses to be Paid [Line Items]
Net expected loss to be paid after recoveries for R&W	42	[2]			58	[2]
Economic loss development after recoveries for R&W	($17)	[2]	($11)	[2]
[1]	Includes expected LAE to be paid of $13 million as of March 31, 2015 and $16 million as of December 31, 2014.
[2]	Refer to Note 8, Financial Guaranty Contracts Accounted for as Credit Derivatives.
[3]	Refer to Note 9, Consolidated Variable Interest Entities.

Expected_Loss_to_be_Paid_Liqui

Expected Loss to be Paid - Liquidation Rates and Key Assumptions in Base Case Expected Loss First Lien RMBS (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2015		Dec. 31, 2014
Financing Receivable, Modified in Previous 12 Months [Member] | Alt-A and Prime [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	25.00%		25.00%
Financing Receivable, Modified in Previous 12 Months [Member] | Option ARM [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	25.00%		25.00%
Financing Receivable, Modified in Previous 12 Months [Member] | Subprime [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	25.00%		25.00%
Financing Receivable, Delinquent in the Previous 12 Months [Member] | Alt-A and Prime [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	25.00%		25.00%
Financing Receivable, Delinquent in the Previous 12 Months [Member] | Option ARM [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	25.00%		25.00%
Financing Receivable, Delinquent in the Previous 12 Months [Member] | Subprime [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	25.00%		25.00%
Financing Receivables, 30 to 59 Days Past Due [Member] | Alt-A and Prime [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	35.00%		35.00%
Financing Receivables, 30 to 59 Days Past Due [Member] | Option ARM [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	40.00%		40.00%
Financing Receivables, 30 to 59 Days Past Due [Member] | Subprime [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	35.00%		35.00%
Financing Receivables, 60 to 89 Days Past Due [Member] | Alt-A and Prime [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	50.00%		50.00%
Financing Receivables, 60 to 89 Days Past Due [Member] | Option ARM [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	55.00%		55.00%
Financing Receivables, 60 to 89 Days Past Due [Member] | Subprime [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	40.00%		40.00%
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Alt-A and Prime [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	60.00%		60.00%
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Option ARM [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	65.00%		65.00%
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Subprime [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	55.00%		55.00%
Financing Receivables, Bankruptcy [Member] | Alt-A and Prime [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	45.00%		45.00%
Financing Receivables, Bankruptcy [Member] | Option ARM [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	50.00%		50.00%
Financing Receivables, Bankruptcy [Member] | Subprime [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	40.00%		40.00%
Financing Receivable, Foreclosure [Member] | Alt-A and Prime [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	75.00%		75.00%
Financing Receivable, Foreclosure [Member] | Option ARM [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	80.00%		80.00%
Financing Receivable, Foreclosure [Member] | Subprime [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	70.00%		70.00%
Financing Receivable, Real Estate Owned [Member]
Schedule of Expected Losses to be Paid [Line Items]
Liquidation Rate	100.00%		100.00%
United States [Member] | Subprime [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Period until intermediate CDR	48 months	[1]	48 months	[1]
Final CPR	15.00%	[1],[2]	15.00%	[1],[2]
United States [Member] | Subprime [Member] | 2005 and prior [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Initial loss severity	75.00%	[1]	75.00%	[1]
United States [Member] | Subprime [Member] | 2006 [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Initial loss severity	90.00%	[1]	90.00%	[1]
United States [Member] | Subprime [Member] | 2007 [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Initial loss severity	90.00%	[1]	90.00%	[1]
United States [Member] | Subprime [Member] | Minimum [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	4.80%	[1]	4.90%	[1]
Intermediate CDR	1.00%	[1]	1.00%	[1]
Final CDR	0.20%	[1]	0.20%	[1]
Initial CPR	0.00%	[1]	0.00%	[1]
United States [Member] | Subprime [Member] | Maximum [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	14.40%	[1]	15.00%	[1]
Intermediate CDR	2.90%	[1]	3.00%	[1]
Final CDR	0.70%	[1]	0.70%	[1]
Initial CPR	9.70%	[1]	10.50%	[1]
United States [Member] | Subprime [Member] | Weighted Average [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	10.20%	[1]	10.60%	[1]
Intermediate CDR	2.00%	[1]	2.10%	[1]
Final CDR	0.40%	[1]	0.40%	[1]
Initial CPR	4.70%	[1]	6.10%	[1]
United States [Member] | Option ARM [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Period until intermediate CDR	48 months	[1]	48 months	[1]
Final CPR	15.00%	[1],[2]	15.00%	[1],[2]
United States [Member] | Option ARM [Member] | 2005 and prior [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Initial loss severity	60.00%	[1]	60.00%	[1]
United States [Member] | Option ARM [Member] | 2006 [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Initial loss severity	70.00%	[1]	70.00%	[1]
United States [Member] | Option ARM [Member] | 2007 [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Initial loss severity	65.00%	[1]	65.00%	[1]
United States [Member] | Option ARM [Member] | Minimum [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	4.50%	[1]	4.30%	[1]
Intermediate CDR	0.90%	[1]	0.90%	[1]
Final CDR	0.20%	[1]	0.20%	[1]
Initial CPR	1.80%	[1]	1.10%	[1]
United States [Member] | Option ARM [Member] | Maximum [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	12.90%	[1]	14.20%	[1]
Intermediate CDR	2.60%	[1]	2.80%	[1]
Final CDR	0.60%	[1]	0.70%	[1]
Initial CPR	12.70%	[1]	11.80%	[1]
United States [Member] | Option ARM [Member] | Weighted Average [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	9.90%	[1]	10.60%	[1]
Intermediate CDR	2.00%	[1]	2.10%	[1]
Final CDR	0.50%	[1]	0.50%	[1]
Initial CPR	4.90%	[1]	4.90%	[1]
United States [Member] | Alt-A [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Period until intermediate CDR	48 months	[1]	48 months	[1]
Final CPR			15.00%	[1],[2]
United States [Member] | Alt-A [Member] | 2005 and prior [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Initial loss severity	60.00%	[1]	60.00%	[1]
United States [Member] | Alt-A [Member] | 2006 [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Initial loss severity	70.00%	[1]	70.00%	[1]
United States [Member] | Alt-A [Member] | 2007 [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Initial loss severity	65.00%	[1]	65.00%	[1]
United States [Member] | Alt-A [Member] | Minimum [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	2.60%	[1]	2.00%	[1]
Intermediate CDR	0.50%	[1]	0.40%	[1]
Final CDR	0.10%	[1]	0.10%	[1]
Initial CPR	2.70%	[1]	1.70%	[1]
Final CPR	15.00%	[1],[2]
United States [Member] | Alt-A [Member] | Maximum [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	13.10%	[1]	13.40%	[1]
Intermediate CDR	2.60%	[1]	2.70%	[1]
Final CDR	0.70%	[1]	0.70%	[1]
Initial CPR	22.40%	[1]	21.00%	[1]
Final CPR	22.40%	[1],[2]
United States [Member] | Alt-A [Member] | Weighted Average [Member] | RMBS [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	7.40%	[1]	7.30%	[1]
Intermediate CDR	1.50%	[1]	1.50%	[1]
Final CDR	0.30%	[1]	0.30%	[1]
Initial CPR	8.10%	[1]	7.70%	[1]
Final CPR	15.20%	[1],[2]
[1]	Represents variables for most heavily weighted scenario (the “base case”).
[2]	For transactions where the initial CPR is higher than the final CPR, the initial CPR is held constant and the final CPR is not used.

Expected_Loss_to_be_Paid_Key_A

Expected Loss to be Paid - Key Assumptions in Base Case Expected Loss Second Lien RMBS (Details) (RMBS [Member], United States [Member])	3 Months Ended		12 Months Ended
	Mar. 31, 2015		Dec. 31, 2014
HELOCs [Member]
Schedule of Expected Losses to be Paid [Line Items]
Expected period until final CDR	34 months	[1]	34 months	[1]
HELOCs [Member] | Minimum [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	2.30%	[1]	2.80%	[1]
Final CDR	0.50%	[1]	0.50%	[1]
Initial CPR	6.90%	[1]	6.90%	[1]
Final CPR	10.00%	[1],[2]	15.00%	[1],[2]
Loss severity	90.00%	[1]	90.00%	[1]
HELOCs [Member] | Maximum [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	7.50%	[1]	6.80%	[1]
Final CDR	3.20%	[1]	3.20%	[1]
Initial CPR	23.20%	[1]	21.80%	[1]
Final CPR	23.20%	[1],[2]	21.80%	[1],[2]
Loss severity	98.00%	[1]	98.00%	[1]
HELOCs [Member] | Weighted Average [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	4.40%	[1]	4.10%	[1]
Final CDR	1.20%	[1]	1.20%	[1]
Initial CPR	10.20%	[1]	11.00%	[1]
Final CPR	15.20%	[1],[2]	15.50%	[1],[2]
Loss severity	90.40%	[1]	90.40%	[1]
Closed-end [Member]
Schedule of Expected Losses to be Paid [Line Items]
Expected period until final CDR	34 months	[1]	34 months	[1]
Final CPR	15.00%	[1],[2]	15.00%	[1],[2]
Loss severity	98.00%	[1]	98.00%	[1]
Closed-end [Member] | Minimum [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	4.70%	[1]	5.50%	[1]
Final CDR	3.50%	[1]	3.50%	[1]
Initial CPR	3.40%	[1]	2.80%	[1]
Closed-end [Member] | Maximum [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	12.40%	[1]	12.50%	[1]
Final CDR	9.10%	[1]	9.10%	[1]
Initial CPR	11.80%	[1]	13.90%	[1]
Closed-end [Member] | Weighted Average [Member]
Schedule of Expected Losses to be Paid [Line Items]
Plateau CDR	6.90%	[1]	7.20%	[1]
Final CDR	4.90%	[1]	4.90%	[1]
Initial CPR	7.60%	[1]	9.90%	[1]
[1]	Represents variables for most heavily weighted scenario (the “base case”).
[2]	For transactions where the initial CPR is higher than the final CPR, the initial CPR is held constant and the final CPR is not used.

Expected_Loss_to_be_Paid_Compo

Expected Loss to be Paid - Components of Development and Accretion Amounts of Estimated Recoveries (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Expected Losses [Abstract]
Estimated increase (decrease) in defaults that will result in additional (lower) breaches(1)	($52)	[1]	$0	[1]
Inclusion or removal of deals with breaches of R&W during period	0		0
Change in recovery assumptions	0		10
Settlements and anticipated settlements	0		35
Accretion of discount on balance	1		3
Total	($51)		$48
[1]	(1)The negative R&W development is offset by higher anticipated cash flows in the covered transactions that were related to a third party settlement.

Expected_Loss_to_be_Paid_Narra

Expected Loss to be Paid - Narrative (Details) (USD $)

3 Months Ended

12 Months Ended

1 Months Ended

Mar. 31, 2015

Mar. 31, 2014

Dec. 31, 2014

Nov. 30, 2014

Dec. 31, 2013

Sep. 12, 2014

Oct. 10, 2013

6-May-13

Apr. 14, 2011

8-May-12

risk

Transaction

Transaction

Schedule of Expected Losses to be Paid [Line Items]

Number of risks subject to R&W recovery

30

29

Risks subject to R&W recovery, related net debt service amount

$2,100,000,000

2,100,000,000

Liability for unpaid claims and claims adjustment expense, net largest single loss

1,154,000,000

[1]

984,000,000

[1]

1,169,000,000

[1]

982,000,000

[1]

Economic loss development after recoveries for R&W

3,000,000

-12,000,000

Net par amount outstanding

389,099,000,000

[2]

403,729,000,000

[3]

Minimum [Member]

Schedule of Expected Losses to be Paid [Line Items]

Discount factor (as a percent)

0.00%

0.00%

Maximum [Member]

Schedule of Expected Losses to be Paid [Line Items]

Discount factor (as a percent)

2.89%

2.95%

Puerto Rico [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

4,940,000,000

4,939,000,000

Gross par outstanding

6,036,000,000

6,035,000,000

RMBS [Member]

Schedule of Expected Losses to be Paid [Line Items]

Amount of liabilities agreed to be paid by entities providing R&W for transaction in which the Company provided insurance

4,200,000,000

RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Maximum number of payments behind to be considered performing borrower

1

Estimated benefit from loan repurchases related to breaches of R&W included in net expected loss estimates

245,000,000

[4]

721,000,000

[4]

317,000,000

712,000,000

Liability for unpaid claims and claims adjustment expense, net largest single loss

570,000,000

[1]

480,000,000

[1]

584,000,000

[1]

493,000,000

[1]

Economic loss development after recoveries for R&W

-4,000,000

10,000,000

Net par amount outstanding

9,078,000,000

9,417,000,000

RMBS [Member] | United States [Member] | Option ARM [Member]

Schedule of Expected Losses to be Paid [Line Items]

Final CPR

15.00%

[5],[6]

15.00%

[5],[6]

RMBS [Member] | United States [Member] | Subprime [Member]

Schedule of Expected Losses to be Paid [Line Items]

Final CPR

15.00%

[5],[6]

15.00%

[5],[6]

RMBS [Member] | United States [Member] | Alt-A [Member]

Schedule of Expected Losses to be Paid [Line Items]

Final CPR

15.00%

[5],[6]

RMBS [Member] | United States [Member] | Closed-end [Member]

Schedule of Expected Losses to be Paid [Line Items]

Final CPR

15.00%

[5],[6]

15.00%

[5],[6]

RMBS [Member] | United States [Member] | Minimum [Member] | Alt-A [Member]

Schedule of Expected Losses to be Paid [Line Items]

Final CPR

15.00%

[5],[6]

RMBS [Member] | United States [Member] | Minimum [Member] | HELOCs [Member]

Schedule of Expected Losses to be Paid [Line Items]

Final CPR

10.00%

[5],[6]

15.00%

[5],[6]

RMBS [Member] | United States [Member] | Maximum [Member] | Alt-A [Member]

Schedule of Expected Losses to be Paid [Line Items]

Final CPR

22.40%

[5],[6]

RMBS [Member] | United States [Member] | Maximum [Member] | HELOCs [Member]

Schedule of Expected Losses to be Paid [Line Items]

Final CPR

23.20%

[5],[6]

21.80%

[5],[6]

HELOCs [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Initial period for which borrower can pay only interest payments

10 years

Percentage of expected default loans reaching amortization period

7.50%

Trust Preferred Securities (TruPS) [Member]

Schedule of Expected Losses to be Paid [Line Items]

Percentage of installment premiums denominated in currencies other than the U.S. dollar

72.00%

Liability for unpaid claims and claims adjustment expense, net largest single loss

14,000,000

[1]

32,000,000

[1]

23,000,000

[1]

51,000,000

[1]

Economic loss development after recoveries for R&W

9,000,000

19,000,000

[7]

Net par amount outstanding

4,075,000,000

4,326,000,000

Triple-X Life Insurance Transaction [Member]

Schedule of Expected Losses to be Paid [Line Items]

Liability for unpaid claims and claims adjustment expense, net largest single loss

165,000,000

[1]

87,000,000

[1]

161,000,000

[1]

75,000,000

[1]

Economic loss development after recoveries for R&W

-5,000,000

-13,000,000

Net par amount outstanding

3,133,000,000

3,133,000,000

Manufactured Housing Loans [Member]

Schedule of Expected Losses to be Paid [Line Items]

Liability for unpaid claims and claims adjustment expense, net largest single loss

25,000,000

Net par amount outstanding

215,000,000

Student Loan [Member]

Schedule of Expected Losses to be Paid [Line Items]

Liability for unpaid claims and claims adjustment expense, net largest single loss

75,000,000

Economic loss development after recoveries for R&W

-8,000,000

Net par amount outstanding

2,500,000,000

Asset-backed Student Loan [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

1,800,000,000

Public Finance Student Loan [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

700,000,000

Public Finance [Member]

Schedule of Expected Losses to be Paid [Line Items]

Liability for unpaid claims and claims adjustment expense, net largest single loss

352,000,000

[1]

338,000,000

[1]

348,000,000

[1]

321,000,000

[1]

Economic loss development after recoveries for R&W

-6,000,000

-23,000,000

Public Finance [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Liability for unpaid claims and claims adjustment expense, net largest single loss

310,000,000

[1]

281,000,000

[1]

303,000,000

[1]

264,000,000

[1]

Economic loss development after recoveries for R&W

-9,000,000

-23,000,000

Net par amount outstanding

313,444,000,000

[2]

322,123,000,000

[3]

Public Finance [Member] | Puerto Rico [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

4,900,000,000

Public Finance Stockton General Fund [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

117,000,000

Cancelled lease revenue bonds

40,000,000

Non-Infrastructure Public Finance [Member] | Spain [Member] | Sovereign and Sub Sovereign [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

331,000,000

Gross par outstanding

461,000,000

Non-Infrastructure Public Finance [Member] | Portugal [Member] | Sovereign and Sub Sovereign [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

102,000,000

Gross par outstanding

114,000,000

Non-Infrastructure Public Finance [Member] | Hungary [Member] | Sovereign and Sub Sovereign [Member]

Schedule of Expected Losses to be Paid [Line Items]

Gross par outstanding

465,000,000

Non-Infrastructure Public Finance [Member] | Spain, Hungry and Portugal [Member] | Sovereign and Sub Sovereign [Member]

Schedule of Expected Losses to be Paid [Line Items]

Liability for unpaid claims and claims adjustment expense, net largest single loss

42,000,000

Economic loss development after recoveries for R&W

-3,000,000

Deutsche Bank [Member]

Schedule of Expected Losses to be Paid [Line Items]

Assets held under trust for reimbursement payment

78,000,000

Number of transactions terminated

1

2

1

Number of transactions insured

8

City of Detroit [Member] | Public Finance [Member] | United States [Member] | Unlimited Tax General Obligation [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

20,000,000

Guarantor obligation on un-exchanged balance, percent

15.50%

Louisville Arena Authority [Member] | Public Finance [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

336,000,000

BIG [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

17,860,000,000

18,247,000,000

BIG [Member] | Puerto Rico [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

4,671,000,000

BIG [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

5,472,000,000

5,643,000,000

BIG [Member] | Trust Preferred Securities (TruPS) [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

1,155,000,000

1,333,000,000

BIG [Member] | Triple-X Life Insurance Transaction [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

598,000,000

598,000,000

BIG [Member] | Manufactured Housing Loans [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

155,000,000

BIG [Member] | Asset-backed Student Loan [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

193,000,000

BIG [Member] | Public Finance Student Loan [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

90,000,000

BIG [Member] | Public Finance [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

7,942,000,000

7,850,000,000

BIG [Member] | Public Finance [Member] | Puerto Rico [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

4,700,000,000

BIG [Member] | Non-Infrastructure Public Finance [Member] | Hungary [Member] | Sovereign and Sub Sovereign [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

439,000,000

BIG [Member] | Ballantyne Re Plc and Orkney Re I I Plc [Member] | Triple-X Life Insurance Transaction [Member]

Schedule of Expected Losses to be Paid [Line Items]

Number of transactions insured

2

Triple-X Life Insurance Transaction [Member] | Life Insurance [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

598,000,000

Refinancing Risk on Infrastructure Transactions [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

3,000,000,000

Financial insurance guaranty, infrastructure finance, possible claims requiring payment, gross before reinsurance

1,700,000,000

Refinancing Risk on Infrastructure Transactions [Member] | Minimum [Member]

Schedule of Expected Losses to be Paid [Line Items]

Estimated years for recoveries of infrastructure transactions

10 years

Refinancing Risk on Infrastructure Transactions [Member] | Maximum [Member]

Schedule of Expected Losses to be Paid [Line Items]

Estimated years for recoveries of infrastructure transactions

35 years

First Lien [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Number of delinquent payments

2

Projected loss assumptions, CDR, plateau rate, projection period

36 months

Projected loss assumptions, Final CDR, Period for voluntary prepayments to continue

12 months

Intermediate conditional default rate (as a percent)

5.00%

Number of scenarios weighted in estimating expected losses

5

Estimated benefit from loan repurchases related to breaches of R&W included in net expected loss estimates

162,000,000

[4]

570,000,000

[4]

232,000,000

569,000,000

Liability for unpaid claims and claims adjustment expense, net largest single loss

569,000,000

[1]

593,000,000

[1]

595,000,000

[1]

620,000,000

[1]

Economic loss development after recoveries for R&W

2,000,000

17,000,000

First Lien [Member] | RMBS [Member] | United States [Member] | Option ARM [Member]

Schedule of Expected Losses to be Paid [Line Items]

Estimated benefit from loan repurchases related to breaches of R&W included in net expected loss estimates

-20,000,000

[4]

152,000,000

[4]

15,000,000

173,000,000

Liability for unpaid claims and claims adjustment expense, net largest single loss

-16,000,000

[1]

-28,000,000

[1]

-16,000,000

[1]

-9,000,000

[1]

Economic loss development after recoveries for R&W

-4,000,000

15,000,000

Net par amount outstanding

374,000,000

407,000,000

First Lien [Member] | RMBS [Member] | United States [Member] | Subprime [Member]

Schedule of Expected Losses to be Paid [Line Items]

Estimated benefit from loan repurchases related to breaches of R&W included in net expected loss estimates

87,000,000

[4]

146,000,000

[4]

109,000,000

118,000,000

Liability for unpaid claims and claims adjustment expense, net largest single loss

293,000,000

[1]

295,000,000

[1]

303,000,000

[1]

304,000,000

[1]

Economic loss development after recoveries for R&W

1,000,000

7,000,000

Net par amount outstanding

3,935,000,000

4,051,000,000

First Lien [Member] | RMBS [Member] | United States [Member] | Prime [Member]

Schedule of Expected Losses to be Paid [Line Items]

Estimated benefit from loan repurchases related to breaches of R&W included in net expected loss estimates

1,000,000

[4]

3,000,000

[4]

2,000,000

4,000,000

Liability for unpaid claims and claims adjustment expense, net largest single loss

3,000,000

[1]

18,000,000

[1]

4,000,000

[1]

21,000,000

[1]

Economic loss development after recoveries for R&W

0

3,000,000

Net par amount outstanding

454,000,000

471,000,000

First Lien [Member] | RMBS [Member] | United States [Member] | Alt-A [Member]

Schedule of Expected Losses to be Paid [Line Items]

Estimated benefit from loan repurchases related to breaches of R&W included in net expected loss estimates

94,000,000

[4]

269,000,000

[4]

106,000,000

274,000,000

Liability for unpaid claims and claims adjustment expense, net largest single loss

289,000,000

[1]

308,000,000

[1]

304,000,000

[1]

304,000,000

[1]

Economic loss development after recoveries for R&W

5,000,000

-8,000,000

Net par amount outstanding

2,449,000,000

2,532,000,000

First Lien [Member] | Base Scenario [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, CDR, plateau rate, projection period

36 months

Period from plateau to intermediate conditional default rate (in months)

12 months

Period of constant intermediate conditional default rate (in months)

36 months

Intermediate conditional default rate as a percentage of plateau conditional default rate

20.00%

Final conditional default rate as a percentage of plateau conditional default rate

5.00%

Final conditional default rate, shortened term

3 months

Default from delinquentor rate, term

36 months

Projected loss assumptions, loss severity, subsequent period

18 months

Estimated loss severity rate, one through six months (as a percent)

18 months

Loss severity (as a percent)

40.00%

Projected loss assumptions, period to reach final loss severity rate

2 years 6 months

Projected loss assumptions, Final CDR, Period for voluntary prepayments to continue

8 years 3 months

Current conditional prepayment rate used in alternate scenario for loss estimate (as a percent)

15.00%

First Lien [Member] | Somewhat Stressful Environment [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, CDR, plateau rate, projection period

42 months

Projected loss assumptions, period to reach final loss severity rate

4 years 6 months

Increase in the plateau period used to calculate potential change in loss estimate (in months)

6 months

Projected loss assumptions, prior period to reach final loss severity rate

2 years 6 months

First Lien [Member] | Somewhat Stressful Environment [Member] | RMBS [Member] | United States [Member] | Option Adjustable Rate Mortgage and Alt-A Mortgage [Member]

Schedule of Expected Losses to be Paid [Line Items]

Loss severity (as a percent)

45.00%

First Lien [Member] | Somewhat Stressful Environment [Member] | RMBS [Member] | United States [Member] | Option ARM [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

2,000,000

First Lien [Member] | Somewhat Stressful Environment [Member] | RMBS [Member] | United States [Member] | Subprime [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

72,000,000

First Lien [Member] | Somewhat Stressful Environment [Member] | RMBS [Member] | United States [Member] | Prime [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

1,000,000

First Lien [Member] | Somewhat Stressful Environment [Member] | RMBS [Member] | United States [Member] | Alt-A [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

38,000,000

First Lien [Member] | Somewhat Stressful Environment [Member] | Subprime [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Loss severity (as a percent)

60.00%

First Lien [Member] | Somewhat Stressful Environment [Member] | Alt-A [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Loss severity (as a percent)

45.00%

First Lien [Member] | More Stressful Environment [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Period from plateau to intermediate conditional default rate (in months)

15 months

Projected loss assumptions, period to reach final loss severity rate

9 years

First Lien [Member] | More Stressful Environment [Member] | RMBS [Member] | United States [Member] | Option ARM [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

12,000,000

First Lien [Member] | More Stressful Environment [Member] | RMBS [Member] | United States [Member] | Subprime [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

99,000,000

First Lien [Member] | More Stressful Environment [Member] | RMBS [Member] | United States [Member] | Prime [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

4,000,000

First Lien [Member] | More Stressful Environment [Member] | RMBS [Member] | United States [Member] | Alt-A [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

84,000,000

First Lien [Member] | Somewhat Less Stressful Environment [Member] | RMBS [Member] | United States [Member] | Option ARM [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

14,000,000

First Lien [Member] | Somewhat Less Stressful Environment [Member] | RMBS [Member] | United States [Member] | Subprime [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

11,000,000

First Lien [Member] | Somewhat Less Stressful Environment [Member] | RMBS [Member] | United States [Member] | Prime [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

100,000

First Lien [Member] | Somewhat Less Stressful Environment [Member] | RMBS [Member] | United States [Member] | Alt-A [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

-400,000

First Lien [Member] | Least Stressful Environment [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, CDR, plateau rate, projection period

30 months

Period from plateau to intermediate conditional default rate (in months)

9 months

Decrease in the plateau period used to calculate potential change in loss estimate (in months)

6 months

First Lien [Member] | Least Stressful Environment [Member] | RMBS [Member] | United States [Member] | Option ARM [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

-26,000,000

First Lien [Member] | Least Stressful Environment [Member] | RMBS [Member] | United States [Member] | Subprime [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

-47,000,000

First Lien [Member] | Least Stressful Environment [Member] | RMBS [Member] | United States [Member] | Prime [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

-500,000

First Lien [Member] | Least Stressful Environment [Member] | RMBS [Member] | United States [Member] | Alt-A [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, increase (decrease) in expected loss to be paid, net

-26,000,000

First Lien [Member] | Bank of America [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Collateral losses

4,200,000,000

First Lien [Member] | Bank of America [Member] | Base Scenario [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Collateral losses

5,200,000,000

First Lien [Member] | UBS [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Agreed reimbursement of R&W, percentage

85.00%

Assets held under trust for reimbursement payment

95,000,000

First Lien [Member] | BIG [Member] | RMBS [Member] | United States [Member] | Option ARM [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

170,000,000

183,000,000

First Lien [Member] | BIG [Member] | RMBS [Member] | United States [Member] | Subprime [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

1,539,000,000

1,575,000,000

First Lien [Member] | BIG [Member] | RMBS [Member] | United States [Member] | Prime [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

349,000,000

353,000,000

First Lien [Member] | BIG [Member] | RMBS [Member] | United States [Member] | Alt-A [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

1,778,000,000

1,841,000,000

Second Lien [Member] | Closed-end [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Final CPR

15.00%

Second Lien [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Period from plateau to intermediate conditional default rate (in months)

28 months

Period of loan default estimate

5 months

Number of preceding months average liquidation rates used to estimate loan default rate

12 months

Number of months CDR is calculated by applying liquidation rates to past due balances

4 months

Stress period (in months)

34 months

Number of months of delinquent data

5 months

Period of constant conditional default rate (in months)

1 month

Conditional prepayment rate base case, average number of quarters

3 months

Number of conditional default rate curves modeled in estimating losses

3

Estimated benefit from loan repurchases related to breaches of R&W included in net expected loss estimates

83,000,000

[4]

151,000,000

[4]

85,000,000

143,000,000

Liability for unpaid claims and claims adjustment expense, net largest single loss

1,000,000

[1]

-113,000,000

[1]

-11,000,000

[1]

-127,000,000

[1]

Economic loss development after recoveries for R&W

-6,000,000

-7,000,000

Second Lien [Member] | RMBS [Member] | United States [Member] | HELOCs [Member]

Schedule of Expected Losses to be Paid [Line Items]

Estimated benefit from loan repurchases related to breaches of R&W included in net expected loss estimates

0

[4]

56,000,000

[4]

0

45,000,000

Liability for unpaid claims and claims adjustment expense, net largest single loss

-10,000,000

[1]

-109,000,000

[1]

-19,000,000

[1]

-116,000,000

[1]

Economic loss development after recoveries for R&W

-5,000,000

-2,000,000

Net par amount outstanding

1,654,000,000

1,738,000,000

Second Lien [Member] | RMBS [Member] | United States [Member] | Closed-end [Member]

Schedule of Expected Losses to be Paid [Line Items]

Estimated benefit from loan repurchases related to breaches of R&W included in net expected loss estimates

83,000,000

[4]

95,000,000

[4]

85,000,000

98,000,000

Liability for unpaid claims and claims adjustment expense, net largest single loss

11,000,000

[1]

-4,000,000

[1]

8,000,000

[1]

-11,000,000

[1]

Economic loss development after recoveries for R&W

-1,000,000

-5,000,000

Net par amount outstanding

212,000,000

218,000,000

Second Lien [Member] | RMBS [Member] | United States [Member] | Home Equity Line of Credit and Closed-end Mortgage [Member]

Schedule of Expected Losses to be Paid [Line Items]

Final CPR

15.00%

Second Lien [Member] | HELOCs [Member]

Schedule of Expected Losses to be Paid [Line Items]

Loss recovery assumption (as a percent)

10.00%

Second Lien [Member] | Base Scenario [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Period from plateau to intermediate conditional default rate (in months)

28 months

Stress period (in months)

34 months

Period of constant conditional default rate (in months)

1 month

Second Lien [Member] | Base Scenario One [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Projected loss assumptions, CDR, plateau rate, projection period

4 months

Period from plateau to intermediate conditional default rate (in months)

33 months

Stress period (in months)

42 months

Increase in conditional default rate ramp down period

5 months

Second Lien [Member] | Base Scenario One [Member] | RMBS [Member] | United States [Member] | HELOCs [Member]

Schedule of Expected Losses to be Paid [Line Items]

Change in estimate for increased conditional default rate plateau period

14,000,000

Second Lien [Member] | Base Scenario One [Member] | RMBS [Member] | United States [Member] | Closed-end [Member]

Schedule of Expected Losses to be Paid [Line Items]

Change in estimate for decreased conditional default rate ramp down period

1,000,000

Second Lien [Member] | Based Scenario Two [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Stress period (in months)

24 months

Period of constant conditional default rate (in months)

1 month

Decreased conditional default rate ramp down period

18 months

Second Lien [Member] | Based Scenario Two [Member] | RMBS [Member] | United States [Member] | HELOCs [Member]

Schedule of Expected Losses to be Paid [Line Items]

Change in estimate for decreased conditional default rate ramp down period

14,000,000

Second Lien [Member] | Based Scenario Two [Member] | RMBS [Member] | United States [Member] | Closed-end [Member]

Schedule of Expected Losses to be Paid [Line Items]

Change in estimate for decreased conditional default rate ramp down period

1,000,000

Second Lien [Member] | Bank of America [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Agreed reimbursement of R&W, percentage

80.00%

Maximum loss up to which loss sharing percentage applicable

6,600,000,000

Second Lien [Member] | Bank of America [Member] | Base Scenario [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Assets held under trust for reimbursement payment

569,000,000

Second Lien [Member] | Guarantor Obligations, Group One [Member] | Deutsche Bank [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Maximum aggregate collateral losses up to which first layer of loss sharing will be applicable

319,000,000

319,000,000

Loss sharing percentage, first layer

80.00%

Second Lien [Member] | Guarantor Obligations, Group Two [Member] | Deutsche Bank [Member] | RMBS [Member] | United States [Member]

Schedule of Expected Losses to be Paid [Line Items]

Maximum aggregate collateral losses up to which first layer of loss sharing will be applicable

389,000,000

Loss sharing percentage, first layer

85.00%

Second Lien [Member] | Guarantor Obligations, Group Two [Member] | Deutsche Bank [Member] | RMBS [Member] | United States [Member] | Maximum [Member]

Schedule of Expected Losses to be Paid [Line Items]

Maximum aggregate collateral losses up to which first layer of loss sharing will be applicable

600,000,000

Second Lien [Member] | BIG [Member] | RMBS [Member] | United States [Member] | HELOCs [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

1,504,000,000

1,557,000,000

Second Lien [Member] | BIG [Member] | RMBS [Member] | United States [Member] | Closed-end [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

132,000,000

134,000,000

Other Assets [Member]

Schedule of Expected Losses to be Paid [Line Items]

Office building, carrying value

30,000,000

Southern District of Mississippi Vs Madison County, Mississippi [Member] | Radian [Member] | Public Finance [Member]

Schedule of Expected Losses to be Paid [Line Items]

Net par amount outstanding

$21,800,000

[1]

Includes expected LAE to be paid of $13 million as of March 31, 2015 and $16 million as of December 31, 2014.

[2]

Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of March 31, 2015, which are primarily in the BIG category.

[3]

Excludes $1.3 billion of loss mitigation securities insured and held by the Company as of December 31, 2014, which are primarily in the BIG category.

[4]

See the section "Breaches of Representations and Warranties" below for eligible assets held in trust.

[5]

For transactions where the initial CPR is higher than the final CPR, the initial CPR is held constant and the final CPR is not used.

[6]

Represents variables for most heavily weighted scenario (the “base case”).

[7]

Refer to Note 8, Financial Guaranty Contracts Accounted for as Credit Derivatives.

Financial_Guaranty_Insurance_L2

Financial Guaranty Insurance Losses - Loss and LAE Reserve and Salvage and Subrogation Recoverable Net of Reinsurance (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	$710	[1]	$721	[1]
Salvage and Subrogation Recoverable, net	128	[1]	154	[1]
Net Reserve (Recoverable)	582	[1]	567	[1]
Financial Guarantee Insurance Product Line [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	709		719
Salvage and Subrogation Recoverable, net	128		148
Net Reserve (Recoverable)	581		571
Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	787		799
Salvage and Subrogation Recoverable, net	129		149
Net Reserve (Recoverable)	658		650
Financial Guarantee Insurance Product Line [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	-78		-80
Salvage and Subrogation Recoverable, net	-1		-1
Net Reserve (Recoverable)	-77		-79
Other Insurance Product Line [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	1		2
Salvage and Subrogation Recoverable, net	0		6
Net Reserve (Recoverable)	1		-4
Trust Preferred Securities (TruPS) [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	0		0
Salvage and Subrogation Recoverable, net	0		0
Net Reserve (Recoverable)	0		0
Triple-X Life Insurance Transaction [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	144		140
Salvage and Subrogation Recoverable, net	0		0
Net Reserve (Recoverable)	144		140
Structured Finance [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	90		96
Salvage and Subrogation Recoverable, net	0		2
Net Reserve (Recoverable)	90		94
Structured Finance [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	506		526
Salvage and Subrogation Recoverable, net	114		128
Net Reserve (Recoverable)	392		398
Public Finance [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	281		273
Salvage and Subrogation Recoverable, net	8		8
Net Reserve (Recoverable)	273		265
Financial Guarantee [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	787		799
Salvage and Subrogation Recoverable, net	122		136
Net Reserve (Recoverable)	665		663
Other [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	0		0
Salvage and Subrogation Recoverable, net	7		13
Net Reserve (Recoverable)	-7		-13
United States [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	272		290
Salvage and Subrogation Recoverable, net	114		126
Net Reserve (Recoverable)	158		164
United States [Member] | Public Finance [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	253		243
Salvage and Subrogation Recoverable, net	8		8
Net Reserve (Recoverable)	245		235
Non United States [Member] | Public Finance [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	28		30
Salvage and Subrogation Recoverable, net	0		0
Net Reserve (Recoverable)	28		30
First Lien [Member] | United States [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	265		283
Salvage and Subrogation Recoverable, net	48		48
Net Reserve (Recoverable)	217		235
Second Lien [Member] | United States [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	7		7
Salvage and Subrogation Recoverable, net	66		78
Net Reserve (Recoverable)	-59		-71
Prime [Member] | First Lien [Member] | United States [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	2		2
Salvage and Subrogation Recoverable, net	0		0
Net Reserve (Recoverable)	2		2
Alt-A [Member] | First Lien [Member] | United States [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	80		87
Salvage and Subrogation Recoverable, net	0		0
Net Reserve (Recoverable)	80		87
Option ARM [Member] | First Lien [Member] | United States [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	24		28
Salvage and Subrogation Recoverable, net	42		40
Net Reserve (Recoverable)	-18		-12
Subprime [Member] | First Lien [Member] | United States [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	159		166
Salvage and Subrogation Recoverable, net	6		8
Net Reserve (Recoverable)	153		158
Closed-end [Member] | Second Lien [Member] | United States [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	5		4
Salvage and Subrogation Recoverable, net	37		39
Net Reserve (Recoverable)	-32		-35
HELOCs [Member] | Second Lien [Member] | United States [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE Reserve, net	2		3
Salvage and Subrogation Recoverable, net	29		39
Net Reserve (Recoverable)	($27)		($36)
[1]	See “Components of Net Reserves (Salvage)” table for loss and LAE reserve and salvage and subrogation recoverable components.

Financial_Guaranty_Insurance_L3

Financial Guaranty Insurance Losses - Components of Net Reserves (Salvage) Insurance Contracts (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE reserve	$787		$799
Reinsurance recoverable on unpaid losses	-77		-78
Loss and LAE reserve, net	710	[1]	721	[1]
Salvage and subrogation recoverable	-128		-151
Salvage and subrogation payable	7	[2]	10	[2]
Other recoveries	-7		-13
Salvage and subrogation recoverable, net and other recoverable	-128		-154
Net reserves (salvage) - financial guaranty	582		567
Other Insurance Product Line [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE reserve, net	1		2
Net reserves (salvage) - financial guaranty	1		-4
Financial Guarantee Insurance Product Line [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE reserve, net	709		719
Other recoveries	-7
Net reserves (salvage) - financial guaranty	$581		$571
[1]	See “Components of Net Reserves (Salvage)” table for loss and LAE reserve and salvage and subrogation recoverable components.
[2]	Recorded as a component of reinsurance balances payable.

Financial_Guaranty_Insurance_L4

Financial Guaranty Insurance Losses - Balance Sheet Classification of Net Expected Recoveries for Breaches of R&W Insurance Contracts (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Salvage and subrogation recoverable, net [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Net expected recoveries for breaches of R&W insurance contracts	$2	[1]	$20	[1]
Salvage and subrogation recoverable, net [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Net expected recoveries for breaches of R&W insurance contracts	0		0
Loss and LAE reserve, net [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Net expected recoveries for breaches of R&W insurance contracts	138	[1]	177	[1]
Loss and LAE reserve, net [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Net expected recoveries for breaches of R&W insurance contracts	-8		-8
Financial Guarantee Insurance Product Line [Member] | Salvage and subrogation recoverable, net [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Net expected recoveries for breaches of R&W insurance contracts	2		20
Financial Guarantee Insurance Product Line [Member] | Loss and LAE reserve, net [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Net expected recoveries for breaches of R&W insurance contracts	$146		$185
[1]	The remaining benefit for R&W is either recorded at fair value in FG VIE assets, or not recorded on the balance sheet until the total loss, net of R&W, exceeds unearned premium reserve.

Financial_Guaranty_Insurance_L5

Financial Guaranty Insurance Losses - Reconciliation of Net Expected Loss to be Paid and Expensed (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014		Mar. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Guarantor Obligations [Line Items]
Net expected loss to be paid after recoveries for R&W	$1,154	[1]	$1,169	[1]	$984	[1]	$982	[1]
Loss and LAE reserve, net of reinsurance	-710	[2]	-721	[2]
Other recoveries	7		13
Net expected loss to be expensed (present value)	315
Variable Interest Entity, Primary Beneficiary [Member]
Guarantor Obligations [Line Items]
Net expected loss to be expensed (present value)	86
Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Guarantor Obligations [Line Items]
Contra-paid, net	-93	[3],[4]	-100	[3],[4]
Financial Guarantee Insurance Product Line [Member]
Guarantor Obligations [Line Items]
Net expected loss to be paid after recoveries for R&W	989
Contra-paid, net	-93
Salvage and subrogation recoverable, net of reinsurance	121
Loss and LAE reserve, net of reinsurance	-709		-719
Other recoveries	7
Net expected loss to be expensed (present value)	315	[5]
Financial Guarantee Insurance Product Line [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Guarantor Obligations [Line Items]
Loss and LAE reserve, net of reinsurance	78		80
Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Guarantor Obligations [Line Items]
Net expected loss to be paid after recoveries for R&W	1,111
Loss and LAE reserve, net of reinsurance	-787		-799
Financial Guarantee Insurance Product Line [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Guarantor Obligations [Line Items]
Net expected loss to be paid after recoveries for R&W	$122
[1]	Includes expected LAE to be paid of $13 million as of March 31, 2015 and $16 million as of December 31, 2014.
[2]	See “Components of Net Reserves (Salvage)” table for loss and LAE reserve and salvage and subrogation recoverable components.
[3]	See Note 6, "Financial Guaranty Insurance Losses– Insurance Contracts' Loss Information" for an explanation of "contra-paid".
[4]	Excludes $125 million and $125 million of deferred premium revenue, and $41 million and $42 million of contra-paid related to FG VIEs as of March 31, 2015 and December 31, 2014, respectively.
[5]	Excludes $86 million as of March 31, 2015, related to consolidated FG VIEs.

Financial_Guaranty_Insurance_L6

Financial Guaranty Insurance Losses - Net Expected Loss to be Expensed Insurance Contracts (Details) (USD $)	Mar. 31, 2015
In Millions, unless otherwise specified
Financial Guaranty Insurance Contracts, Premiums [Line Items]
2015 (April 1 - June 30)	$7
2015 (July 1 - September 30)	9
2015 (October 1 - December 31)	11
Subtotal 2015	27
2016	36
2017	27
2018	25
2019	23
2020-2024	77
2025-2029	45
2030-2034	34
After 2034	21
Net expected loss to be expensed	315
Discount	389
Total future value	$704

Financial_Guaranty_Insurance_L7

Financial Guaranty Insurance Losses - Loss and LAE Reported on the Statements of Operations (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	$18	$41
Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	23	40
Variable Interest Entity, Primary Beneficiary [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	-5	1
Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	24	41
Other Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	-1	-1
RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member] | United States [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	7	-1
Trust Preferred Securities (TruPS) [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	-1	-1
Triple-X Life Insurance Transaction [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	6	13
Other structured finance [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	-6	3
Structured Finance [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	6	14
Public Finance [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	18	27
Public Finance [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member] | United States [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	13	26
Public Finance [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member] | Non United States [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	5	1
First Lien [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member] | United States [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	-3	-9
Second Lien [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member] | United States [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	10	8
Prime [Member] | First Lien [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member] | United States [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	0	0
Alt-A [Member] | First Lien [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member] | United States [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	-2	7
Option ARM [Member] | First Lien [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member] | United States [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	-1	-8
Subprime [Member] | First Lien [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member] | United States [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	0	-8
Closed-end [Member] | Second Lien [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member] | United States [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	1	0
HELOCs [Member] | Second Lien [Member] | RMBS [Member] | Financial Guarantee Insurance Product Line [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member] | United States [Member]
Liability for Claims and Claims Adjustment Expense Including Salvage and Subrogation Recoverable [Line Items]
Loss and LAE	$9	$8

Financial_Guaranty_Insurance_L8

Financial Guaranty Insurance Losses - BIG Transaction Loss Summary (Details) (USD $)	3 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
	risk		risk
Discount
Total	($389)
Reserves (salvage)
Total	582		567
BIG [Member]
Number of risks
Total (in contracts)	356	[1]	358	[1]
Remaining weighted average contract period
Total (in years)	10 years 1 month 6 days		10 years 3 months 18 days
Principal
Total	14,937		15,222
Interest
Total	7,393		7,651
Total net outstanding exposure
Total	22,330	[2]	22,873	[2]
Expected cash outflows (inflows)
Total	3,001		3,118
Potential recoveries
Total, Undiscounted R&W	-165		-239
Total, Other	-1,458	[3]	-1,477	[3]
Total	-1,623		-1,716
Subtotal
Total	1,378		1,402
Discount
Total	-389		-413
Present value of expected cash flows
Net expected loss to be paid	989		989
Deferred premium revenue
Total	557		584
Reserves (salvage)
Total	581	[4]	571	[4]
BIG [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member]
Number of risks
Total (in contracts)	356	[1]	358	[1]
Remaining weighted average contract period
Total (in years)	10 years 1 month 6 days		10 years 3 months 18 days
Principal
Total	14,937		15,222
Interest
Total	7,393		7,651
Total net outstanding exposure
Total	22,330	[2]	22,873	[2]
Expected cash outflows (inflows)
Total	3,344		3,463
Potential recoveries
Total, Undiscounted R&W	-173		-247
Total, Other	-1,638	[3]	-1,654	[3]
Total	-1,811		-1,901
Subtotal
Total	1,533		1,562
Discount
Total	-422		-447
Present value of expected cash flows
Net expected loss to be paid	1,111		1,115
Deferred premium revenue
Total	668		700
Reserves (salvage)
Total	658	[4]	650	[4]
BIG [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member] | BIG 1 [Member]
Number of risks
Ceded (in contracts)	-61	[1]	-59	[1]
Total (in contracts)	164	[1]	164	[1]
Remaining weighted average contract period
Gross (in years)	9 years 9 months 12 days		9 years 10 months 24 days
Ceded (in years)	7 years 2 months 12 days		7 years 4 months 24 days
Principal
Gross	11,993		12,358
Ceded	-2,106		-2,163
Interest
Gross	6,082		6,350
Ceded	-792		-838
Total net outstanding exposure
Gross	18,075	[2]	18,708	[2]
Ceded	-2,898	[2]	-3,001	[2]
Expected cash outflows (inflows)
Gross	1,655		1,762
Ceded	-616		-626
Total	64		39
Potential recoveries
Gross, Undiscounted R&W	-1		-39
Ceded, Undiscounted R&W	-1		0
Gross, Other	-1,583	[3]	-1,687	[3]
Ceded, Other	600	[3]	608	[3]
Ceded	599		608
Gross	-1,584		-1,726
Subtotal
Gross	71		36
Ceded	-17		-18
Discount
Gross	-7		3
Ceded	0		0
Present value of expected cash flows
Ceded	-17		-18
Deferred premium revenue
Gross	402		378
Ceded	-75		-70
Reserves (salvage)
Gross	-10	[4]	-42	[4]
Ceded	-7	[4]	-5	[4]
BIG [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member] | BIG 2 [Member]
Number of risks
Ceded (in contracts)	-15	[1]	-15	[1]
Total (in contracts)	73	[1]	75	[1]
Remaining weighted average contract period
Gross (in years)	8 years 8 months 12 days		10 years 1 month 6 days
Ceded (in years)	7 years 2 months 12 days		8 years 10 months 24 days
Principal
Gross	2,701		2,421
Ceded	-356		-286
Interest
Gross	1,262		1,274
Ceded	-127		-121
Total net outstanding exposure
Gross	3,963	[2]	3,695	[2]
Ceded	-483	[2]	-407	[2]
Expected cash outflows (inflows)
Gross	759		763
Ceded	-84		-77
Total	345		392
Potential recoveries
Gross, Undiscounted R&W	-47		-48
Ceded, Undiscounted R&W	2		2
Gross, Other	-271	[3]	-206	[3]
Ceded, Other	18	[3]	5	[3]
Ceded	20		7
Gross	-318		-254
Subtotal
Gross	441		509
Ceded	-64		-70
Discount
Gross	-96		-117
Ceded	10		11
Present value of expected cash flows
Ceded	-54		-59
Deferred premium revenue
Gross	104		119
Ceded	-6		-6
Reserves (salvage)
Gross	269	[4]	278	[4]
Ceded	-52	[4]	-53	[4]
BIG [Member] | Consolidated Entity Excluding Consolidation of Variable Interest Entities (VIE) [Member] | BIG 3 [Member]
Number of risks
Ceded (in contracts)	-38	[1]	-38	[1]
Total (in contracts)	119	[1]	119	[1]
Remaining weighted average contract period
Gross (in years)	9 years 10 months 24 days		9 years 7 months 6 days
Ceded (in years)	7 years 3 months 18 days		6 years 10 months 24 days
Principal
Gross	2,847		3,067
Ceded	-142		-175
Interest
Gross	1,013		1,034
Ceded	-45		-48
Total net outstanding exposure
Gross	3,860	[2]	4,101	[2]
Ceded	-187	[2]	-223	[2]
Expected cash outflows (inflows)
Gross	1,721		1,716
Ceded	-91		-75
Total	803		788
Potential recoveries
Gross, Undiscounted R&W	-133		-171
Ceded, Undiscounted R&W	7		9
Gross, Other	-449	[3]	-404	[3]
Ceded, Other	47	[3]	30	[3]
Ceded	54		39
Gross	-582		-575
Subtotal
Gross	1,139		1,141
Ceded	-37		-36
Discount
Gross	-336		-353
Ceded	7		9
Present value of expected cash flows
Ceded	-30		-27
Deferred premium revenue
Gross	268		312
Ceded	-25		-33
Reserves (salvage)
Gross	468	[4]	482	[4]
Ceded	-10	[4]	-10	[4]
BIG [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Expected cash outflows (inflows)
Total	-343		-345
Potential recoveries
Total, Undiscounted R&W	8		8
Total, Other	180	[3]	177	[3]
Total	188		185
Subtotal
Total	-155		-160
Discount
Total	33		34
Present value of expected cash flows
Net expected loss to be paid	-122		-126
Deferred premium revenue
Total	-111		-116
Reserves (salvage)
Total	($77)	[4]	($79)	[4]
[1]	A risk represents the aggregate of the financial guaranty policies that share the same revenue source for purposes of making Debt Service payments. The ceded number of risks represents the number of risks for which the Company ceded a portion of its exposure
[2]	Includes BIG amounts related to FG VIEs.
[3]	Includes excess spread and draws on HELOCs.
[4]	See table “Components of net reserves (salvage).”

Financial_Guaranty_Insurance_L9

Financial Guaranty Insurance Losses - Narrative (Details) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Guarantor Obligations [Line Items]
Financial guaranty insurance expected LAE reserve, amount	10,000,000	12,000,000
Guaranteed investment contract, aggregate accreted balance	2,100,000,000
Assets of GIC issuers, aggregate accreted principal	3,300,000,000
Assets of GIC issuers, aggregate market value	3,200,000,000
Variable rate demand obligations
Guarantor Obligations [Line Items]
Rate basis for bank bond rate	prime rate
Minimum [Member]
Guarantor Obligations [Line Items]
Weighted average risk-free rates for U.S. dollar denominated financial guaranty insurance obligations	0.00%	0.00%
Minimum [Member] | Variable rate demand obligations
Guarantor Obligations [Line Items]
Bank bond rate (as a percent)	2.00%
Threshold period of bonds held by bank for right of accelerated repayment (in days)	90 days
Maximum [Member]
Guarantor Obligations [Line Items]
Weighted average risk-free rates for U.S. dollar denominated financial guaranty insurance obligations	2.89%	2.95%
Maximum [Member] | Variable rate demand obligations
Guarantor Obligations [Line Items]
Bank bond rate (as a percent)	3.00%
Bank bond capped rate (as a percent)	25.00%
Threshold period of bonds held by bank for right of accelerated repayment (in days)	180 days
Cash | Minimum [Member]
Guarantor Obligations [Line Items]
Collateralization as a percentage of GIC balance	100.00%
Asset-backed Securities [Member] | Maximum [Member]
Guarantor Obligations [Line Items]
Collateralization as a percentage of GIC balance	108.00%
Termination of Swap Obligation due to Rating Downgrade [Member] | AGM [Member]
Guarantor Obligations [Line Items]
Maximum possible estimated termination payment on swap obligations after taking account the rating downgrade in January 2013	163,000,000
Termination of Swap Obligation due to Further Rating Downgrade [Member] | AGM [Member]
Guarantor Obligations [Line Items]
Maximum possible estimated termination payment on swap obligations after taking account the rating downgrade in January 2013	416,000,000
Financial Guarantee [Member] | AGM and AGC [Member]
Guarantor Obligations [Line Items]
Financial guarantee insurance contracts principal amount insured	5,900,000,000
Internal Credit, B Minus Rating [Member] | Financial Guarantee [Member] | AGM and AGC [Member]
Guarantor Obligations [Line Items]
Financial guarantee insurance contracts principal amount insured	300,000,000

Fair_Value_Measurement_Measure

Fair Value Measurement - Measured and Carried at Fair Value (Details) (USD $)	3 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Percentage of CDS contracts which are fair valued using minimum premium	20.00%		21.00%
CDS contracts [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Gross spread percentage	100.00%	[1]	100.00%	[1]
Number of sources of credit spread	3
Based on actual collateral specific spreads [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Gross spread percentage	9.00%	[1]	9.00%	[1]
Based on market indices [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Gross spread percentage	81.00%	[1]	82.00%	[1]
Provided by the CDS counterparty [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Gross spread percentage	10.00%	[1]	9.00%	[1]
Scenario 1 [Member] | CDS contracts [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Bank profit as % of total	62.00%
Hedge cost as % of total	16.00%
Premium received per annum as % of total	22.00%
Original gross spread/cash bond price (as a percent)	1.85%
Bank profit (as a percent)	1.15%
Hedge cost (as a percent)	0.30%
The Company premium received per annum (as a percent)	0.40%
Scenario 1 [Member] | CDS contracts [Member] | AGC [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Original gross spread/cash bond price (as a percent)	3.00%
Percentage of exposure hedged	10.00%
Scenario 2 [Member] | CDS contracts [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Bank profit as % of total	10.00%
Hedge cost as % of total	88.00%
Premium received per annum as % of total	2.00%
Original gross spread/cash bond price (as a percent)	5.00%
Bank profit (as a percent)	0.50%
Hedge cost (as a percent)	4.40%
The Company premium received per annum (as a percent)	0.10%
Scenario 2 [Member] | CDS contracts [Member] | AGC [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Original gross spread/cash bond price (as a percent)	17.60%
Percentage of exposure hedged	25.00%
Recurring [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Other invested assets	102		95
Recurring [Member] | Level 3 [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Number of fixed maturity securities valued using model processes	34
Fixed maturity securities	696
Recurring [Member] | Level 3 [Member] | CDS contracts [Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount factor (as a percent)	0.18%		0.26%
Recurring [Member] | Level 3 [Member] | CDS contracts [Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount factor (as a percent)	2.32%		2.70%
Available-for-Sale Debt Securities and Short Term Investments [Member] | Recurring [Member] | Level 3 [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Percentage of fixed maturity securities valued using model processes to the Company's fixed-income securities and short-term investments at fair value	6.80%
[1]	Based on par.

Fair_Value_Measurement_Financi

Fair Value Measurement - Financial Instruments Carried at Fair Value (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Assets:
Fixed-maturity securities	$10,182		$11,258
Other invested assets	132		126
Credit derivative assets	77		68
Liabilities:
Credit derivative liabilities	859		963
Recurring [Member]
Assets:
Other invested assets	107	[1]	100	[1]
Credit derivative assets	77		68
FG VIEs’ assets, at fair value	1,495		1,398	[2]
Other assets	84		78
Total assets carried at fair value	11,945		12,902
Liabilities:
Credit derivative liabilities	859		963
FG VIEs’ liabilities with recourse, at fair value	1,278		1,277
FG VIEs’ liabilities without recourse, at fair value	145		142
Total liabilities carried at fair value	2,282		2,382
Recurring [Member] | Level 1 [Member]
Assets:
Other invested assets	0	[1]	0	[1]
Credit derivative assets	0		0
FG VIEs’ assets, at fair value	0		0	[2]
Other assets	30		26
Total assets carried at fair value	202		385
Liabilities:
Credit derivative liabilities	0		0
FG VIEs’ liabilities with recourse, at fair value	0		0
FG VIEs’ liabilities without recourse, at fair value	0		0
Total liabilities carried at fair value	0		0
Recurring [Member] | Level 2 [Member]
Assets:
Other invested assets	26	[1]	17	[1]
Credit derivative assets	0		0
FG VIEs’ assets, at fair value	0		0	[2]
Other assets	17		17
Total assets carried at fair value	9,357		10,163
Liabilities:
Credit derivative liabilities	0		0
FG VIEs’ liabilities with recourse, at fair value	0		0
FG VIEs’ liabilities without recourse, at fair value	0		0
Total liabilities carried at fair value	0		0
Recurring [Member] | Level 3 [Member]
Assets:
Other invested assets	81	[1]	83	[1]
Credit derivative assets	77		68
FG VIEs’ assets, at fair value	1,495		1,398	[2]
Other assets	37		35
Total assets carried at fair value	2,386		2,354
Liabilities:
Credit derivative liabilities	859		963
FG VIEs’ liabilities with recourse, at fair value	1,278		1,277
FG VIEs’ liabilities without recourse, at fair value	145		142
Total liabilities carried at fair value	2,282		2,382
Fixed Maturities [Member]
Assets:
Fixed-maturity securities	9,833		10,491
Fixed Maturities [Member] | Obligations of state and political subdivisions [Member]
Assets:
Fixed-maturity securities	5,458		5,795
Fixed Maturities [Member] | US Treasury and Government [Member]
Assets:
Fixed-maturity securities	497		665
Fixed Maturities [Member] | Corporate securities [Member]
Assets:
Fixed-maturity securities	1,399		1,368
Fixed Maturities [Member] | RMBS [Member]
Assets:
Fixed-maturity securities	1,185	[3]	1,285	[3]
Fixed Maturities [Member] | CMBS [Member]
Assets:
Fixed-maturity securities	600	[3]	659	[3]
Fixed Maturities [Member] | Asset-backed Securities [Member]
Assets:
Fixed-maturity securities	401		417
Fixed Maturities [Member] | Foreign government securities [Member]
Assets:
Fixed-maturity securities	293		302
Fixed Maturities [Member] | Recurring [Member]
Assets:
Fixed-maturity securities	9,833		10,491
Fixed Maturities [Member] | Recurring [Member] | Obligations of state and political subdivisions [Member]
Assets:
Fixed-maturity securities	5,458		5,795
Fixed Maturities [Member] | Recurring [Member] | US Treasury and Government [Member]
Assets:
Fixed-maturity securities	497		665
Fixed Maturities [Member] | Recurring [Member] | Corporate securities [Member]
Assets:
Fixed-maturity securities	1,399		1,368
Fixed Maturities [Member] | Recurring [Member] | RMBS [Member]
Assets:
Fixed-maturity securities	1,185		1,285
Fixed Maturities [Member] | Recurring [Member] | CMBS [Member]
Assets:
Fixed-maturity securities	600		659
Fixed Maturities [Member] | Recurring [Member] | Asset-backed Securities [Member]
Assets:
Fixed-maturity securities	401		417
Fixed Maturities [Member] | Recurring [Member] | Foreign government securities [Member]
Assets:
Fixed-maturity securities	293		302
Fixed Maturities [Member] | Recurring [Member] | Level 1 [Member]
Assets:
Fixed-maturity securities	0		0
Fixed Maturities [Member] | Recurring [Member] | Level 1 [Member] | Obligations of state and political subdivisions [Member]
Assets:
Fixed-maturity securities	0		0
Fixed Maturities [Member] | Recurring [Member] | Level 1 [Member] | US Treasury and Government [Member]
Assets:
Fixed-maturity securities	0		0
Fixed Maturities [Member] | Recurring [Member] | Level 1 [Member] | Corporate securities [Member]
Assets:
Fixed-maturity securities	0		0
Fixed Maturities [Member] | Recurring [Member] | Level 1 [Member] | RMBS [Member]
Assets:
Fixed-maturity securities	0		0
Fixed Maturities [Member] | Recurring [Member] | Level 1 [Member] | CMBS [Member]
Assets:
Fixed-maturity securities	0		0
Fixed Maturities [Member] | Recurring [Member] | Level 1 [Member] | Asset-backed Securities [Member]
Assets:
Fixed-maturity securities	0		0
Fixed Maturities [Member] | Recurring [Member] | Level 1 [Member] | Foreign government securities [Member]
Assets:
Fixed-maturity securities	0		0
Fixed Maturities [Member] | Recurring [Member] | Level 2 [Member]
Assets:
Fixed-maturity securities	9,137		9,721
Fixed Maturities [Member] | Recurring [Member] | Level 2 [Member] | Obligations of state and political subdivisions [Member]
Assets:
Fixed-maturity securities	5,450		5,757
Fixed Maturities [Member] | Recurring [Member] | Level 2 [Member] | US Treasury and Government [Member]
Assets:
Fixed-maturity securities	497		665
Fixed Maturities [Member] | Recurring [Member] | Level 2 [Member] | Corporate securities [Member]
Assets:
Fixed-maturity securities	1,320		1,289
Fixed Maturities [Member] | Recurring [Member] | Level 2 [Member] | RMBS [Member]
Assets:
Fixed-maturity securities	802		860
Fixed Maturities [Member] | Recurring [Member] | Level 2 [Member] | CMBS [Member]
Assets:
Fixed-maturity securities	600		659
Fixed Maturities [Member] | Recurring [Member] | Level 2 [Member] | Asset-backed Securities [Member]
Assets:
Fixed-maturity securities	175		189
Fixed Maturities [Member] | Recurring [Member] | Level 2 [Member] | Foreign government securities [Member]
Assets:
Fixed-maturity securities	293		302
Fixed Maturities [Member] | Recurring [Member] | Level 3 [Member]
Assets:
Fixed-maturity securities	696		770
Fixed Maturities [Member] | Recurring [Member] | Level 3 [Member] | Obligations of state and political subdivisions [Member]
Assets:
Fixed-maturity securities	8		38
Fixed Maturities [Member] | Recurring [Member] | Level 3 [Member] | US Treasury and Government [Member]
Assets:
Fixed-maturity securities	0		0
Fixed Maturities [Member] | Recurring [Member] | Level 3 [Member] | Corporate securities [Member]
Assets:
Fixed-maturity securities	79		79
Fixed Maturities [Member] | Recurring [Member] | Level 3 [Member] | RMBS [Member]
Assets:
Fixed-maturity securities	383		425
Fixed Maturities [Member] | Recurring [Member] | Level 3 [Member] | CMBS [Member]
Assets:
Fixed-maturity securities	0		0
Fixed Maturities [Member] | Recurring [Member] | Level 3 [Member] | Asset-backed Securities [Member]
Assets:
Fixed-maturity securities	226		228
Fixed Maturities [Member] | Recurring [Member] | Level 3 [Member] | Foreign government securities [Member]
Assets:
Fixed-maturity securities	0		0
Short-term Investments [Member]
Assets:
Fixed-maturity securities	349		767
Short-term Investments [Member] | Recurring [Member]
Assets:
Fixed-maturity securities	349		767
Short-term Investments [Member] | Recurring [Member] | Level 1 [Member]
Assets:
Fixed-maturity securities	172		359
Short-term Investments [Member] | Recurring [Member] | Level 2 [Member]
Assets:
Fixed-maturity securities	177		408
Short-term Investments [Member] | Recurring [Member] | Level 3 [Member]
Assets:
Fixed-maturity securities	$0		$0
[1]	Includes Level 3 mortgage loans that are recorded at fair value on a non-recurring basis.
[2]	Exclude restricted cash.
[3]	Government-agency obligations were approximately 47% of mortgage backed securities as of March 31, 2015 and 44% as of December 31, 2014 based on fair value.

Fair_Value_Measurement_Fair_Va

Fair Value Measurement - Fair Value Level 3 Rollforward Recurring Basis (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
FG VIEs' liabilities with recourse, at fair value [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	($1,277)		($1,790)
Net income (loss)	93	[1],[2]	-72	[1],[2]
Other comprehensive income (loss)	0	[1]	0	[1]
Purchases	0		0
Settlements	37		269
FG VIE consolidations	-131		0
FG VIE deconsolidations	0		247
Fair value at end of period	-1,278		-1,346
Change in unrealized gains/(losses) related to financial instruments held	-6		-28
FG VIEs' liabilities without recourse, at fair value [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value at beginning of period	-142		-1,081
Net income (loss)	-5	[1],[2]	-9	[1],[2]
Other comprehensive income (loss)	0	[1]	0	[1]
Purchases	0		0
Settlements	2		12
FG VIE consolidations	0		0
FG VIE deconsolidations	0		977
Fair value at end of period	-145		-101
Change in unrealized gains/(losses) related to financial instruments held	-4		-10
Credit Risk Contract [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Fair value at beginning of period	-895		-1,693
Net income (loss)	124	[1],[3]	-211	[1],[3]
Other comprehensive income (loss)	0	[1]	0	[1]
Purchases	0		0
Settlements	-11		-19
FG VIE consolidations	0		0
FG VIE deconsolidations	0		0
Fair value at end of period	-782		-1,923
Change in unrealized gains/(losses) related to financial instruments held	103		-232
Obligations of state and political subdivisions [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period	38		36
Net Income (loss)	3	[1],[4]	1	[1],[4]
Other comprehensive income (loss)	-2	[1]	1	[1]
Purchases	0		0
Settlements	-31	[5]	0
FG VIE Consolidations	0		0
FG VIE deconsolidations	0		0
Fair value at end of period	8		38
Change in unrealized gains/(losses) related to financial instruments held	0		1
Corporate securities [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period	79		136
Net Income (loss)	2	[1],[4]	3	[1],[4]
Other comprehensive income (loss)	-2	[1]	4	[1]
Purchases	0		0
Settlements	0		-5
FG VIE Consolidations	0		0
FG VIE deconsolidations	0		0
Fair value at end of period	79		138
Change in unrealized gains/(losses) related to financial instruments held	-2		4
RMBS [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period	425		290
Net Income (loss)	9	[1],[4]	4	[1],[4]
Other comprehensive income (loss)	5	[1]	14	[1]
Purchases	9		53
Settlements	-65		-15
FG VIE Consolidations	0		0
FG VIE deconsolidations	0		13
Fair value at end of period	383		359
Change in unrealized gains/(losses) related to financial instruments held	7		15
Asset-backed Securities [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period	228		268
Net Income (loss)	-2	[1],[4]	7	[1],[4]
Other comprehensive income (loss)	1	[1]	8	[1]
Purchases	0		0
Settlements	-1		-31
FG VIE Consolidations	0		0
FG VIE deconsolidations	0		0
Fair value at end of period	226		252
Change in unrealized gains/(losses) related to financial instruments held	1		7
Other invested assets [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period	78		2
Net Income (loss)	-4	[1],[4]	0	[1]
Other comprehensive income (loss)	2	[1]	1	[1]
Purchases	0		45	[5]
Settlements	0		0
FG VIE Consolidations	0		0
FG VIE deconsolidations	0		0
Fair value at end of period	76		48
Change in unrealized gains/(losses) related to financial instruments held	2		1
FG VIEs' assets, at fair value [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period	1,398		2,565
Net Income (loss)	23	[1],[2]	82	[1],[2]
Other comprehensive income (loss)	0	[1]	0	[1]
Purchases	0		0
Settlements	-30		-286
FG VIE Consolidations	104		0
FG VIE deconsolidations	0		-1,104
Fair value at end of period	1,495		1,257
Change in unrealized gains/(losses) related to financial instruments held	34		25
Other assets [Member]
Fair Value Level 3 Rollforward
Fair value at beginning of period	35		46
Net Income (loss)	2	[1],[6]	-9	[1],[6]
Other comprehensive income (loss)	0	[1]	0	[1]
Purchases	0		0
Settlements	0		0
FG VIE Consolidations	0		0
FG VIE deconsolidations	0		0
Fair value at end of period	37		37
Change in unrealized gains/(losses) related to financial instruments held	$2		($9)
[1]	Realized and unrealized gains (losses) from changes in values of Level 3 financial instruments represent gains (losses) from changes in values of those financial instruments only for the periods in which the instruments were classified as Level 3.
[2]	Included in fair value gains (losses) on FG VIEs.
[3]	Reported in net change in fair value of credit derivatives.
[4]	Included in net realized investment gains (losses) and net investment income.
[5]	on-cash transaction.
[6]	Recorded in fair value gains (losses) on CCS.

Quantitative_Information_Asset

- Quantitative Information - Assets (Details) (Income Approach Valuation Technique [Member], Level 3 [Member], USD $)	3 Months Ended		12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Obligations of state and political subdivisions [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset, fair value	8	[1]	38	[1]
Yield (as a percent)	4.60%
Obligations of state and political subdivisions [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Rate of inflation (as a percent)	1.00%		1.00%
Cash flow receipts (as a percent)	0.50%		0.50%
Yield (as a percent)			4.60%
Collateral recovery period (in years)	4 months		1 month
Obligations of state and political subdivisions [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Rate of inflation (as a percent)	3.00%		3.00%
Cash flow receipts (as a percent)	20.90%		74.30%
Yield (as a percent)			8.00%
Collateral recovery period (in years)	8 years 4 months		34 years
Obligations of state and political subdivisions [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Rate of inflation (as a percent)	2.00%		2.00%
Cash flow receipts (as a percent)	12.90%		63.00%
Yield (as a percent)			7.30%
Collateral recovery period (in years)	4 years 3 months 12 days		28 years
Corporate securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset, fair value	79	[1]	79	[1]
Yield (as a percent)	18.00%		17.80%
RMBS [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset, fair value	383	[1]	425	[1]
RMBS [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield (as a percent)	4.20%		4.70%
Conditional prepayment rate (as a percent)	0.30%		0.30%
Conditional default rate (as a percent)	2.40%		2.70%
Loss severity rate (as a percent)	50.00%		52.60%
RMBS [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield (as a percent)	10.00%		11.70%
Conditional prepayment rate (as a percent)	7.50%		8.10%
Conditional default rate (as a percent)	11.60%		10.60%
Loss severity rate (as a percent)	100.00%		100.00%
RMBS [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield (as a percent)	5.90%		6.40%
Conditional prepayment rate (as a percent)	3.40%		3.30%
Conditional default rate (as a percent)	5.50%		5.30%
Loss severity rate (as a percent)	72.40%		75.20%
Investor-owned utilities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset, fair value	96	[1]	95	[1]
Cash flow receipts (as a percent)	100.00%		100.00%
Discount factor (as a percent)	7.00%		7.00%
Collateral recovery period (in years)	3 years 9 months		4 years
XXX life insurance transactions [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset, fair value	130	[1]	133	[1]
Yield (as a percent)	6.80%		7.30%
Other invested assets [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset, fair value	81	[1]	83	[1]
Liquidity discount (as a percent)	20.00%		20.00%
Recovery on delinquent loans (as a percent)	40.00%		40.00%
Other invested assets [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Conditional prepayment rate (as a percent)	6.00%		5.00%
Conditional default rate (as a percent)	0.00%		0.00%
Loss severity rate (as a percent)	40.00%		40.00%
Net asset value (per share)	966		965
Other invested assets [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Conditional prepayment rate (as a percent)	15.00%		15.00%
Conditional default rate (as a percent)	7.00%		7.00%
Loss severity rate (as a percent)	75.00%		75.00%
Net asset value (per share)	1,147		1,159
Other invested assets [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Conditional prepayment rate (as a percent)	12.00%		12.30%
Conditional default rate (as a percent)	6.10%		5.80%
Loss severity rate (as a percent)	68.70%		68.30%
Net asset value (per share)	1,046		1,082
Financial Guaranty Variable Interest Entities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset, fair value	1,495	[1]	1,398	[1]
Financial Guaranty Variable Interest Entities [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield (as a percent)	2.70%		2.70%
Conditional prepayment rate (as a percent)	0.30%		0.30%
Conditional default rate (as a percent)	1.70%		1.60%
Loss severity rate (as a percent)	36.00%		40.00%
Financial Guaranty Variable Interest Entities [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield (as a percent)	16.70%		17.70%
Conditional prepayment rate (as a percent)	11.00%		11.00%
Conditional default rate (as a percent)	13.10%		11.80%
Loss severity rate (as a percent)	100.00%		100.00%
Financial Guaranty Variable Interest Entities [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield (as a percent)	6.40%		7.90%
Conditional prepayment rate (as a percent)	2.60%		3.30%
Conditional default rate (as a percent)	4.20%		5.10%
Loss severity rate (as a percent)	64.20%		82.20%
Other Assets [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset, fair value	37	[1]	35	[1]
Fair Value Inputs Term	5 years		5 years
Other Assets [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quotes from third party pricing (in dollars per share)	51		52
Other Assets [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quotes from third party pricing (in dollars per share)	60		61
Other Assets [Member] | Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quotes from third party pricing (in dollars per share)	56		57
[1]	Discounted cash flow is used as valuation technique for all financial instruments.

Quantitative_Information_Liabi

- Quantitative Information - Liabilities (Details) (Income Approach Valuation Technique [Member], USD $)	3 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Credit derivative liabilities, net [Member] | Level 3 [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Total liabilities carried at fair value	-782	[1]	-895	[1]
Credit derivative liabilities, net [Member] | Minimum [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Internal floor (as a percent)	0.07%		0.07%
Bank profit (as a percent)	0.01%		0.01%
Hedge cost (as a percent)	0.15%		0.20%
Credit derivative liabilities, net [Member] | Minimum [Member] | Level 3 [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Year 1 loss estimates (as a percent)	0.00%		0.00%
Credit derivative liabilities, net [Member] | Maximum [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Internal floor (as a percent)	1.00%		1.00%
Bank profit (as a percent)	9.90%		9.94%
Hedge cost (as a percent)	2.56%		2.44%
Credit derivative liabilities, net [Member] | Maximum [Member] | Level 3 [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Year 1 loss estimates (as a percent)	50.00%		93.00%
Credit derivative liabilities, net [Member] | Weighted Average [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Internal floor (as a percent)	0.16%		0.16%
Bank profit (as a percent)	1.25%		1.27%
Hedge cost (as a percent)	0.57%		0.62%
Credit derivative liabilities, net [Member] | Weighted Average [Member] | Level 3 [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Year 1 loss estimates (as a percent)	1.70%		2.10%
Financial Guaranty Variable Interest Entities [Member] | Level 3 [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Total liabilities carried at fair value	-1,423	[1]	-1,419	[1]
Financial Guaranty Variable Interest Entities [Member] | Minimum [Member] | Level 3 [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Loss severity rate (as a percent)	36.00%		40.00%
Conditional default rate (as a percent)	1.70%		1.60%
Conditional prepayment rate (as a percent)	0.30%		0.30%
Yield (as a percent)	2.70%		2.70%
Financial Guaranty Variable Interest Entities [Member] | Maximum [Member] | Level 3 [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Loss severity rate (as a percent)	100.00%		100.00%
Conditional default rate (as a percent)	13.10%		11.80%
Conditional prepayment rate (as a percent)	11.00%		11.00%
Yield (as a percent)	16.70%		17.70%
Financial Guaranty Variable Interest Entities [Member] | Weighted Average [Member] | Level 3 [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Loss severity rate (as a percent)	64.20%		82.20%
Conditional default rate (as a percent)	4.20%		5.10%
Conditional prepayment rate (as a percent)	2.60%		3.30%
Yield (as a percent)	5.50%		5.80%
[1]	Discounted cash flow is used as valuation technique for all financial instruments.

Fair_Value_Measurement_Fair_Va1

Fair Value Measurement - Fair Value of Financial Instruments (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Assets:
Fixed-maturity securities	$10,182		$11,258
Short-term investments	349		767
Other invested assets	132		126
Credit derivative assets	77		68
Liabilities:
Credit derivative liabilities	859		963
Carrying Amount [Member]
Assets:
Fixed-maturity securities	9,833		10,491
Short-term investments	349		767
Other invested assets	114		108
Credit derivative assets	77		68
FG VIEs’ assets, at fair value	1,495		1,398
Other assets	189		184
Liabilities:
Financial guaranty insurance contracts	3,719	[1]	3,823	[1]
Long-term debt	1,304		1,303
Credit derivative liabilities	859		963
FG VIEs’ liabilities with recourse, at fair value	1,278		1,277
FG VIEs’ liabilities without recourse, at fair value	145		142
Other liabilities	72		27
Estimated Fair Value [Member]
Assets:
Fixed-maturity securities	9,833		10,491
Short-term investments	349		767
Other invested assets	116		110
Credit derivative assets	77		68
FG VIEs’ assets, at fair value	1,495		1,398
Other assets	189		184
Liabilities:
Financial guaranty insurance contracts	6,343	[1]	6,205	[1]
Long-term debt	1,609		1,603
Credit derivative liabilities	859		963
FG VIEs’ liabilities with recourse, at fair value	1,278		1,277
FG VIEs’ liabilities without recourse, at fair value	145		142
Other liabilities	$72		$27
[1]	Carrying amount includes the assets and liabilities related to financial guaranty insurance contract premiums, losses, and salvage and subrogation and other recoverables net of reinsurance.

Financial_Guaranty_Contracts_A2

Financial Guaranty Contracts Accounted for as Credit Derivatives - Credit Derivatives Subordination and Ratings (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	$31,731		$34,996
Pooled corporate obligations [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	20,735		23,621
Original Subordination (as a percent)	30.20%	[1]	30.10%	[1]
Current Subordination (as a percent)	31.20%	[1]	30.70%	[1]
Pooled corporate obligations [Member] | Collateralized loan obligations and collateral bond obligations [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	10,372		11,688
Original Subordination (as a percent)	32.00%	[1]	32.00%	[1]
Current Subordination (as a percent)	37.70%	[1]	36.90%	[1]
Pooled corporate obligations [Member] | Synthetic investment grade pooled corporate [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	6,363		7,640
Original Subordination (as a percent)	22.30%	[1]	22.60%	[1]
Current Subordination (as a percent)	20.20%	[1]	20.60%	[1]
Pooled corporate obligations [Member] | TruPS CDOs [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	2,948		3,119
Original Subordination (as a percent)	45.60%	[1]	45.30%	[1]
Current Subordination (as a percent)	37.50%	[1]	35.80%	[1]
Pooled corporate obligations [Member] | Market Value of CDOs of corporate obligations [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	1,052		1,174
Original Subordination (as a percent)	17.00%	[1]	19.10%	[1]
Current Subordination (as a percent)	15.70%	[1]	20.70%	[1]
RMBS [Member] | United States [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	2,868		2,986
Original Subordination (as a percent)	24.80%	[1]	24.80%	[1]
Current Subordination (as a percent)	33.30%	[1]	33.90%	[1]
RMBS [Member] | Option Adjustable Rate Mortgage and Alt-A Mortgage [Member] | United States [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	1,321		1,378
Original Subordination (as a percent)	16.20%	[1]	16.30%	[1]
Current Subordination (as a percent)	10.50%	[1]	10.70%	[1]
RMBS [Member] | Subprime [Member] | United States [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	1,315		1,366
Original Subordination (as a percent)	31.30%	[1]	31.10%	[1]
Current Subordination (as a percent)	49.90%	[1]	50.50%	[1]
RMBS [Member] | Prime [Member] | United States [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	213		223
Original Subordination (as a percent)	10.90%	[1]	10.90%	[1]
Current Subordination (as a percent)	0.00%	[1]	0.00%	[1]
RMBS [Member] | Closed-end [Member] | United States [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	19		19
Original Subordination (as a percent)	0.00%	[1]	0.00%	[1]
Current Subordination (as a percent)	0.00%	[1]	0.00%	[1]
CMBS [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	1,785		1,952
Original Subordination (as a percent)	35.90%	[1]	35.30%	[1]
Current Subordination (as a percent)	45.50%	[1]	43.60%	[1]
Other [Member]
Net Par Outstanding on Credit Derivatives
Net Par Outstanding	$6,343		$6,437
Original Subordination (as a percent)	0.00%	[1]	0.00%	[1]
Current Subordination (as a percent)	0.00%	[1]	0.00%	[1]
[1]	Represents the sum of subordinate tranches and over-collateralization and does not include any benefit from excess interest collections that may be used to absorb losses.

Financial_Guaranty_Contracts_A3

Financial Guaranty Contracts Accounted for as Credit Derivatives - Distribution of Credit Derivative Net Par Outstanding by Internal Rating (Details) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Credit Derivatives
Net Par Outstanding	31,731	34,996
Internal Credit Rating, AAA [Member]
Credit Derivatives
Net Par Outstanding	19,132	21,817
Internal Credit Rating, AA [Member]
Credit Derivatives
Net Par Outstanding	5,195	5,398
Internal Credit Rating, A [Member]
Credit Derivatives
Net Par Outstanding	1,865	1,982
Internal Credit Rating, BBB [Member]
Credit Derivatives
Net Par Outstanding	2,616	2,774
BIG [Member]
Credit Derivatives
Net Par Outstanding	2,923	3,025
Credit Concentration Risk [Member] | Derivative, Aggregate Notional Amount [Member]
Credit Derivatives
Percentage of installment premiums denominated in currencies other than the U.S. dollar	100.00%	100.00%
Credit Concentration Risk [Member] | Derivative, Aggregate Notional Amount [Member] | Internal Credit Rating, AAA [Member]
Credit Derivatives
Percentage of installment premiums denominated in currencies other than the U.S. dollar	60.30%	62.30%
Credit Concentration Risk [Member] | Derivative, Aggregate Notional Amount [Member] | Internal Credit Rating, AA [Member]
Credit Derivatives
Percentage of installment premiums denominated in currencies other than the U.S. dollar	16.40%	15.40%
Credit Concentration Risk [Member] | Derivative, Aggregate Notional Amount [Member] | Internal Credit Rating, A [Member]
Credit Derivatives
Percentage of installment premiums denominated in currencies other than the U.S. dollar	5.90%	5.70%
Credit Concentration Risk [Member] | Derivative, Aggregate Notional Amount [Member] | Internal Credit Rating, BBB [Member]
Credit Derivatives
Percentage of installment premiums denominated in currencies other than the U.S. dollar	8.20%	8.00%
Credit Concentration Risk [Member] | Derivative, Aggregate Notional Amount [Member] | BIG [Member]
Credit Derivatives
Percentage of installment premiums denominated in currencies other than the U.S. dollar	9.20%	8.60%

Financial_Guaranty_Contracts_A4

Financial Guaranty Contracts Accounted for as Credit Derivatives - Net Change in Fair Value of Credit Derivatives Gains (Losses) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Credit Derivatives
Realized gains on credit derivatives	$23	[1]	$20	[1]
Net credit derivative losses (paid and payable) recovered and recoverable and other settlements	-2		-1
Realized gains (losses) and other settlements on credit derivatives	21		19
Net change in unrealized gains (losses) on credit derivatives	103		-230
Net change in fair value of credit derivatives	124		-211
Pooled corporate obligations [Member]
Credit Derivatives
Net change in unrealized gains (losses) on credit derivatives	17		-58
CMBS [Member]
Credit Derivatives
Net change in unrealized gains (losses) on credit derivatives	0		0
Other [Member]
Credit Derivatives
Net change in unrealized gains (losses) on credit derivatives	11		-32
United States [Member] | RMBS [Member]
Credit Derivatives
Net change in unrealized gains (losses) on credit derivatives	75		-140
Credit Risk Contract [Member]
Credit Derivatives
Net par of terminated CDS contracts	93		1,100
Realized gains (losses) and other settlements	$11		$0.20
[1]	Includes realized gain due to terminations of CDS contracts of $11 million and $0.2 million for First Quarter 2015 and First Quarter 2014, respectively. Net par of $93 million and $1.1 billion were terminated in First Quarter 2015 and First Quarter 2014, respectively. CDS terminations reflect a payment received from the resolution of a dispute related to a termination of CDS in 2008.

Financial_Guaranty_Contracts_A5

Financial Guaranty Contracts Accounted for as Credit Derivatives - CDS Spread and Components of Credit Derivative Assets (Liabilities) (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Credit Derivatives
Fair value of credit derivatives before effect of AGC and AGM credit spreads	-1,820		-2,029
Plus: Effect of AGC and AGM credit spreads	1,038		1,134
Net fair value of credit derivatives	-782	[1]	-895
Credit Risk Contract, 5 Year Spread [Member] | AGC [Member]
Credit Derivatives
Quoted price of CDS contract (as a percent)	3.17%		3.23%	2.91%	4.60%
Credit Risk Contract, 5 Year Spread [Member] | AGM [Member]
Credit Derivatives
Quoted price of CDS contract (as a percent)	3.41%		3.25%	3.05%	5.25%
Credit Risk Contract, 1 Year Spread [Member] | AGC [Member]
Credit Derivatives
Quoted price of CDS contract (as a percent)	0.60%		0.80%	0.55%	1.85%
Credit Risk Contract, 1 Year Spread [Member] | AGM [Member]
Credit Derivatives
Quoted price of CDS contract (as a percent)	0.80%		0.85%	0.70%	2.20%
[1]	Includes the effects of spreads on both the underlying asset classes and the Company’s own credit spread.

Financial_Guaranty_Contracts_A6

Financial Guaranty Contracts Accounted for as Credit Derivatives - Net Fair Value and Expected Losses of Credit Derivatives by Sector (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Credit Derivatives
Net fair value of credit derivatives	($782)	[1]	($895)
Expected Loss to be (Paid) Recovered	-42	[2]	-58	[2]
Pooled corporate obligations [Member]
Credit Derivatives
Net fair value of credit derivatives	-22		-49
Expected Loss to be (Paid) Recovered	-13	[2]	-23	[2]
RMBS [Member] | United States [Member]
Credit Derivatives
Net fair value of credit derivatives	-419		-494
Expected Loss to be (Paid) Recovered	-66	[2]	-73	[2]
CMBS [Member]
Credit Derivatives
Net fair value of credit derivatives	0		0
Expected Loss to be (Paid) Recovered	0	[2]	0	[2]
Other [Member]
Credit Derivatives
Net fair value of credit derivatives	-341		-352
Expected Loss to be (Paid) Recovered	37	[2]	38	[2]
Credit Risk Contract [Member]
Credit Derivatives
R&W Included in Credit Derivative Asset (Liability)	$75		$86
[1]	Includes the effects of spreads on both the underlying asset classes and the Company’s own credit spread.
[2]	Includes R&W benefit of $75 million as of March 31, 2015 and $86 million as of December 31, 2014.

Financial_Guaranty_Contracts_A7

Financial Guaranty Contracts Accounted for as Credit Derivatives - Effect of Changes in Credit Spread (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Credit Risk Derivatives, 100 Percent Widening in Spreads, Effect on Fair Value	($1,590)	[1]
Credit Risk Derivatives, 50 Percent Widening in Spreads, Effect on Fair Value	-1,186	[1]
Credit Risk Derivatives, 25 Percent Widening in Spreads, Effect on Fair Value	-986	[1]
Credit Risk Derivatives, 10 Percent Widening in Spreads, Effect on Fair Value	-864	[1]
Net fair value of credit derivatives	-782	[1]	-895
Credit Risk Derivatives, 10 Percent Narrowing in Spreads, Effect on Fair Value	-706	[1]
Credit Risk Derivatives, 25 Percent Narrowing in Spreads, Effect on Fair Value	-593	[1]
Credit Risk Derivatives, 50 Percent Narrowing in Spreads, Effect on Fair Value	-407	[1]
Credit Risk Derivatives, 100 Percent Widening in Spreads, Effect on Unrealized Gain (Loss)	-808	[1]
Credit Risk Derivatives, 50 Percent Widening in Spreads, Effect on Unrealized Gain (Loss)	-404	[1]
Credit Risk Derivatives, 25 Percent Widening in Spreads, Effect on Unrealized Gain (Loss)	-204	[1]
Credit Risk Derivatives, 10 Percent Widening in Spreads, Effect on Unrealized Gain (Loss)	-82	[1]
Credit Risk Derivatives, Base Scenario, Effect on Unrealized Gain (Loss)	0	[1]
Credit Risk Derivatives, 10 Percent Narrowing in Spreads, Effect on Unrealized Gain (Loss)	76	[1]
Credit Risk Derivatives, 25 Percent Narrowing in Spreads, Effect on Unrealized Gain (Loss)	189	[1]
Credit Risk Derivatives, 50 Percent Narrowing in Spreads, Effect on Unrealized Gain (Loss)	$375	[1]
[1]	Includes the effects of spreads on both the underlying asset classes and the Company’s own credit spread.

Financial_Guaranty_Contracts_A8

Financial Guaranty Contracts Accounted for as Credit Derivatives - Narrative (Details) (USD $)	3 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Credit Derivatives
Estimated remaining weighted average life of credit derivatives (in years)	4 years 7 months 30 days		4 years 7 months 30 days
Net par outstanding	$31,731		$34,996
Net unrealized gains (losses)	103	-230
Net change in fair value of credit derivatives	124	-211
Gain due to change in methodology in expected recoveries	49
Gain from narrowing of spreads	209
Collateral agreed to be posted	356		376
Market value collateralized debt obligations of corporate obligations [Member]
Credit Derivatives
Maximum average obligor size (as a percent)	1.00%
Maximum exposure of one industry (as a percent)	10.00%
Net par outstanding	20,735		23,621
Net unrealized gains (losses)	17	-58
Other pooled infrastructure [Member]
Credit Derivatives
Net par outstanding	1,900
Pooled infrastructure [Member]
Credit Derivatives
Number of transactions	1
Remaining other CDS [Member]
Credit Derivatives
Net par outstanding	4,400
Collateral Debt Obligations, Collateral Requirement [Member]
Credit Derivatives
Amount of par subject to collateral for which the amount of collateral is capped	5,700
Collateral Debt Obligations, Collateral Cap Negotiated [Member]
Credit Derivatives
Amount of par subject to collateral for which the amount of collateral is capped	5,500
Collateral Debt Obligations, No Cap Negotiated [Member]
Credit Derivatives
Amount of par subject to collateral for which the amount of collateral is capped	665
Collateral agreed to be posted	356		376
Notional amount subject to collateral based on movements in the mark-to-market valuation of the underlying exposure	241		242
Collateral posted, based on mark-to-market valuation	21		25
Credit Risk Contract [Member]
Credit Derivatives
Realized gains (losses) and other settlements	$11	$0.20

Consolidated_Variable_Interest2

Consolidated Variable Interest Entities - Narrative (Details) (USD $)	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014	Dec. 31, 2013
	Entity		Entity		Entity	Entity
Variable Interest Entity [Line Items]
Variable Interest Entity, Number of Entities to be Consolidated	1
Net fair value gains and losses on FG VIEs are expected to reverse to zero at maturity of the VIE debt	$0
Credit Risk Derivatives at Fair Value before Effect of Credit Spread Net 1 [Abstract]
Fair value gains (losses) on FG VIEs	-7,000,000		157,000,000
Number of entities to be deconsolidated			7
Number of FG VIE's matured			-2
Effect on shareholders’ equity (decrease) increase	5,786,000,000				5,758,000,000
Net earned premiums	142,000,000		132,000,000
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Initial Consolidation, Gain (Loss)	26,000,000
Variable Interest Entity, Number of Entities to be Consolidated	1	[1]	0	[1]
Net gain on deconsolidation			120,000,000
Credit Risk Derivatives at Fair Value before Effect of Credit Spread Net 1 [Abstract]
Fair value gains (losses) on FG VIEs	-7,000,000		157,000,000
Gain from Company's exercise of options			37,000,000
Number of FG VIE's matured	0		-2
Effect on shareholders’ equity (decrease) increase	-49,000,000				-44,000,000
Net earned premiums	-5,000,000		-17,000,000
Number of VIE that did not require consolidation	33		31		32	40
Variable Interest Entity, Not Primary Beneficiary, Aggregated Disclosure [Member]
Credit Risk Derivatives at Fair Value before Effect of Credit Spread Net 1 [Abstract]
Number of VIE that did not require consolidation	900				930
Residential Mortgage Backed Securities and Other Insurance Products [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Credit Risk Derivatives at Fair Value before Effect of Credit Spread Net 1 [Abstract]
Total unpaid principal balance for the VIEs' assets that were over 90 days or more past due	218,000,000				183,000,000
Difference between the aggregate unpaid principal and aggregate fair value of the VIEs' Assets	942,000,000				941,000,000
Change in the instrument specific credit risk of the VIEs' assets	18,000,000		58,000,000
Unpaid principal for FG VIEs’ liabilities with recourse	2,017,000,000				1,912,000,000
Unpaid principal for FG VIEs' liabilities with and without recourse	$1,014,000,000				$916,000,000
[1]	Net loss on consolidation was $26 million in First Quarter 2015, and net gain on deconsolidation was $120 million in First Quarter 2014, and recorded in “fair value gains (losses) on FG VIEs” in the consolidated statement of operations.

Consolidated_Variable_Interest3

Consolidated Variable Interest Entities - Number of FG VIE's Consolidated (Details)	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
	Entity		Entity
Number of FG VIEs Consolidated [Roll Forward]
Number of FG VIE's consolidated	1
Number of FG VIE's matured			-2
Variable Interest Entity, Primary Beneficiary [Member]
Number of FG VIEs Consolidated [Roll Forward]
Number of FG VIE's consolidated, beginning of period	32		40
Number of FG VIE's consolidated	1	[1]	0	[1]
Number of FG VIE's deconsolidated	0	[1]	-7	[1]
Number of FG VIE's matured	0		-2
Number of FG VIE's consolidated, end of period	33		31
[1]	Net loss on consolidation was $26 million in First Quarter 2015, and net gain on deconsolidation was $120 million in First Quarter 2014, and recorded in “fair value gains (losses) on FG VIEs” in the consolidated statement of operations.

Consolidated_Variable_Interest4

Consolidated Variable Interest Entities - Consolidated FG VIE's By Type of Collateral (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Variable Interest Entity [Line Items]
Financial guaranty variable interest entities' assets with recourse, at fair value	$1,332	$1,239
Financial guaranty variable interest entities’ liabilities with recourse, at fair value	1,278	1,277
Financial guaranty variable interest entities' assets without recourse, at fair value	167	163
Financial guaranty variable interest entities’ liabilities without recourse, at fair value	145	142
Financial guaranty variable interest entities’ assets, at fair value	1,499	1,402
Financial guaranty variable interest entities’ liabilities, at fair value	1,423	1,419
Other Insurance Product Line [Member]
Variable Interest Entity [Line Items]
Financial guaranty variable interest entities' assets with recourse, at fair value	365	369
Financial guaranty variable interest entities’ liabilities with recourse, at fair value	365	369
United States [Member] | First Lien [Member] | RMBS [Member]
Variable Interest Entity [Line Items]
Financial guaranty variable interest entities' assets with recourse, at fair value	739	632
Financial guaranty variable interest entities’ liabilities with recourse, at fair value	591	581
United States [Member] | Second Lien [Member] | RMBS [Member]
Variable Interest Entity [Line Items]
Financial guaranty variable interest entities' assets with recourse, at fair value	228	238
Financial guaranty variable interest entities’ liabilities with recourse, at fair value	$322	$327

Consolidated_Variable_Interest5

Consolidated Variable Interest Entities - Effect of Consolidating FG VIE's on Financial Information (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Variable Interest Entity [Line Items]
Net earned premiums	$142	$132
Net investment income	101	103
Net realized investment gains (losses)	16	2
Fair value gains (losses) on FG VIEs	-7	157
Other income (loss)	-9	21
Loss and LAE	18	41
Income (loss) before income taxes	266	69
Provision (benefit) for income taxes	65	27
Net income (loss)	201	42
Net cash flows provided by (used in) operating activities	23	101
Effect on shareholders’ equity (decrease) increase	5,786		5,758
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Net earned premiums	-5	-17
Net investment income	-3	-3
Fair value gains (losses) on FG VIEs	-7	157
Other income (loss)	0	-2
Loss and LAE	5	-1
Income (loss) before income taxes	-10	134
Provision (benefit) for income taxes	-4	47
Net income (loss)	-6	87
Net cash flows provided by (used in) operating activities	18	-8
Effect on shareholders’ equity (decrease) increase	($49)		($44)

Investments_and_Cash_Net_Inves

Investments and Cash - Net Investment Income (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Net Investment Income
Gross investment income	$103	$105
Investment expenses	-2	-2
Net investment income	101	103
Fixed Maturities, Managed Externally [Member]
Net Investment Income
Gross investment income	82	80
Fixed Maturities, Managed Internally [Member]
Net Investment Income
Gross investment income	15	20
Other Invested Assets, Internally Managed [Member]
Net Investment Income
Gross investment income	$6	$5

Investments_and_Cash_Net_Reali

Investments and Cash - Net Realized Investment Gains (Losses) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Net Realized Investment Gains (Losses)
Gross realized gains on available-for-sale securities	$24	$4
Gross realized gains on other assets in investment portfolio	1	5
Gross realized losses on available-for-sale securities	-1	-2
Gross realized losses on other assets in investment portfolio	-1	0
Other-than-temporary impairment	-7	-5
Net realized investment gains (losses)	$16	$2

Investments_and_Cash_Roll_Forw

Investments and Cash - Roll Forward of Credit Losses in the Investment Portfolio (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Roll Forward of Credit Losses in the Investment Portfolio
Credit losses, beginning of period	$124	$80
Additions for credit losses on securities for which an other-than-temporary-impairment was not previously recognized	0	1
Reductions for securities sold and other settlement during the period	-21	0
Additions for credit losses on securities for which an other-than-temporary-impairment was previously recognized	3	4
Credit losses, end of period	$106	$85

Investments_and_Cash_Fixed_Mat

Investments and Cash - Fixed Maturity Securities and Short Term Investments (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Investments
Percent of Total	100.00%	[1]	100.00%	[1]
Amortized Cost	$9,659		$10,739
Gross Unrealized Gains	555		552
Gross Unrealized Losses	-32		-33
Fixed-maturity securities	10,182		11,258
AOCI Gain (Loss) on Securities with Other-Than-Temporary Impairment	8	[2]	8
Fixed Maturities [Member]
Investments
Percent of Total	96.00%	[1]	93.00%	[1]
Amortized Cost	9,310		9,972
Gross Unrealized Gains	555		552
Gross Unrealized Losses	-32		-33
Fixed-maturity securities	9,833		10,491
AOCI Gain (Loss) on Securities with Other-Than-Temporary Impairment	8	[2]	8
Short-term Investments [Member]
Investments
Percent of Total	4.00%	[1]	7.00%	[1]
Amortized Cost	349		767
Gross Unrealized Gains	0		0
Gross Unrealized Losses	0		0
Fixed-maturity securities	349		767
AOCI Gain (Loss) on Securities with Other-Than-Temporary Impairment	0	[2]	0
Obligations of state and political subdivisions [Member] | Fixed Maturities [Member]
Investments
Percent of Total	52.00%	[1]	50.00%	[1]
Amortized Cost	5,099		5,416
Gross Unrealized Gains	361		380
Gross Unrealized Losses	-2		-1
Fixed-maturity securities	5,458		5,795
AOCI Gain (Loss) on Securities with Other-Than-Temporary Impairment	4	[2]	7
US Treasury and Government [Member] | Fixed Maturities [Member]
Investments
Percent of Total	5.00%	[1]	6.00%	[1]
Amortized Cost	464		635
Gross Unrealized Gains	33		31
Gross Unrealized Losses	0		-1
Fixed-maturity securities	497		665
AOCI Gain (Loss) on Securities with Other-Than-Temporary Impairment	0	[2]	0
Corporate securities [Member] | Fixed Maturities [Member]
Investments
Percent of Total	14.00%	[1]	12.00%	[1]
Amortized Cost	1,340		1,320
Gross Unrealized Gains	65		53
Gross Unrealized Losses	-6		-5
Fixed-maturity securities	1,399		1,368
AOCI Gain (Loss) on Securities with Other-Than-Temporary Impairment	-4	[2]	-2
RMBS [Member] | Fixed Maturities [Member]
Investments
Percent of Total	12.00%	[1],[3]	12.00%	[1],[3]
Amortized Cost	1,145	[3]	1,255	[3]
Gross Unrealized Gains	56	[3]	51	[3]
Gross Unrealized Losses	-16	[3]	-21	[3]
Fixed-maturity securities	1,185	[3]	1,285	[3]
AOCI Gain (Loss) on Securities with Other-Than-Temporary Impairment	5	[2],[3]	0	[3]
CMBS [Member] | Fixed Maturities [Member]
Investments
Percent of Total	6.00%	[1],[3]	6.00%	[1],[3]
Amortized Cost	573	[3]	639	[3]
Gross Unrealized Gains	27	[3]	20	[3]
Gross Unrealized Losses	0	[3]	0	[3]
Fixed-maturity securities	600	[3]	659	[3]
AOCI Gain (Loss) on Securities with Other-Than-Temporary Impairment	0	[2],[3]	0	[3]
Asset-backed Securities [Member] | Fixed Maturities [Member]
Investments
Percent of Total	4.00%	[1]	4.00%	[1]
Amortized Cost	394		411
Gross Unrealized Gains	7		9
Gross Unrealized Losses	0		-3
Fixed-maturity securities	401		417
AOCI Gain (Loss) on Securities with Other-Than-Temporary Impairment	3	[2]	3
Foreign government securities [Member] | Fixed Maturities [Member]
Investments
Percent of Total	3.00%	[1]	3.00%	[1]
Amortized Cost	295		296
Gross Unrealized Gains	6		8
Gross Unrealized Losses	-8		-2
Fixed-maturity securities	293		302
AOCI Gain (Loss) on Securities with Other-Than-Temporary Impairment	$0	[2]	$0
[1]	Based on amortized cost.
[2]	Accumulated OCI. See also Note 17, Shareholders' Equity.
[3]	Government-agency obligations were approximately 47% of mortgage backed securities as of March 31, 2015 and 44% as of December 31, 2014 based on fair value.

Investments_and_Cash_Gross_Unr

Investments and Cash - Gross Unrealized Loss by Length of Time (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified	Security		Security
Less than 12 months
Fair value	$680		$797
Unrealized loss	-17		-10
12 months or more
Fair Value	109		393
Unrealized loss	-15		-23
Total
Fair value	789		1,190
Unrealized loss	-32		-33
Number of securities
Less than 12 months (in securities)	166	[1]	125	[1]
12 months or more (in securities)	24	[1]	82	[1]
Total (in securities)	187	[1]	198	[1]
Number of securities with OTTI
Less than 12 months (in securities)	2		3
12 months or more (in securities)	3		7
Total (in securities)	5		10
Obligations of state and political subdivisions [Member]
Less than 12 months
Fair value	189		64
Unrealized loss	-2		0
12 months or more
Fair Value	5		25
Unrealized loss	0		-1
Total
Fair value	194		89
Unrealized loss	-2		-1
US Treasury and Government [Member]
Less than 12 months
Fair value	26		139
Unrealized loss	0		0
12 months or more
Fair Value	12		68
Unrealized loss	0		-1
Total
Fair value	38		207
Unrealized loss	0		-1
Corporate securities [Member]
Less than 12 months
Fair value	194		189
Unrealized loss	-6		-3
12 months or more
Fair Value	5		104
Unrealized loss	0		-2
Total
Fair value	199		293
Unrealized loss	-6		-5
RMBS [Member]
Less than 12 months
Fair value	94		205
Unrealized loss	-1		-3
12 months or more
Fair Value	85		159
Unrealized loss	-15		-18
Total
Fair value	179		364
Unrealized loss	-16		-21
CMBS [Member]
Less than 12 months
Fair value	21		36
Unrealized loss	0		0
12 months or more
Fair Value	2		19
Unrealized loss	0		0
Total
Fair value	23		55
Unrealized loss	0		0
Asset-backed Securities [Member]
Less than 12 months
Fair value	0		56
Unrealized loss	0		-2
12 months or more
Fair Value	0		18
Unrealized loss	0		-1
Total
Fair value	0		74
Unrealized loss	0		-3
Foreign government securities [Member]
Less than 12 months
Fair value	156		108
Unrealized loss	-8		-2
12 months or more
Fair Value	0		0
Unrealized loss	0		0
Total
Fair value	156		108
Unrealized loss	($8)		($2)
[1]	The number of securities does not add across because lots of the same securities have been purchased at different times and appear in both categories above (i.e. Less than 12 months and 12 months or more). If a security appears in both categories, it is counted only once in the total column.

Investments_and_Cash_Distribut

Investments and Cash - Distribution of Fixed-Maturity Securities by Contractual Maturity (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Millions, unless otherwise specified
Amortized Cost
Amortized cost	$9,310		$9,972
Estimated Fair Value
Estimated fair value	10,182		11,258
Fixed Maturities [Member]
Amortized Cost
Due within one year	156
Due after one year through five years	1,706
Due after five years through 10 years	2,146
Due after 10 years	3,584
Amortized cost	9,310
Estimated Fair Value
Due within one year	158
Due after one year through five years	1,763
Due after five years through 10 years	2,288
Due after 10 years	3,839
Estimated fair value	9,833		10,491
Fixed Maturities [Member] | RMBS [Member]
Amortized Cost
Amortized cost	1,145
Estimated Fair Value
Estimated fair value	1,185	[1]	1,285	[1]
Fixed Maturities [Member] | CMBS [Member]
Amortized Cost
Amortized cost	573
Estimated Fair Value
Estimated fair value	$600	[1]	$659	[1]
[1]	Government-agency obligations were approximately 47% of mortgage backed securities as of March 31, 2015 and 44% as of December 31, 2014 based on fair value.

Investments_and_Cash_Internall

Investments and Cash - Internally Managed Investment Portfolio (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Schedule of Cost-method Investments [Line Items]
Fixed-maturity securities	$10,182	$11,258
Other invested assets	132	126
Internally managed portfolio	10,314	11,384
Fixed Maturities, Managed Internally [Member]
Schedule of Cost-method Investments [Line Items]
Fixed-maturity securities	721	835
Other Invested Assets, Internally Managed [Member]
Schedule of Cost-method Investments [Line Items]
Other invested assets	41	46
Other, Internally Managed [Member]
Schedule of Cost-method Investments [Line Items]
Other invested assets	91	79
Internally Managed Portfolio [Member]
Schedule of Cost-method Investments [Line Items]
Internally managed portfolio	$853	$960

Investments_and_Cash_Narrative

Investments and Cash - Narrative (Details) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Investment [Line Items]
Government Agency Obligations as a Percentage of Total Mortgage Backed Securities	47.00%	44.00%
Accrued investment income	93	98
Number of securities with unrealized losses greater than 10% of book value for 12 months or more	4
Total unrealized losses for securities having losses greater than 10% of book value for 12 months or more	14
Assets held-in-trust	215	236
Fair market value of company's pledged securities	356	376
Number of Outside Managers Managing Investment Portfolio	4
Investments [Member] | Internally Managed Portfolio [Member]
Investment [Line Items]
Percentage of installment premiums denominated in currencies other than the U.S. dollar	8.00%	8.00%
AGL Subsidiaries [Member]
Investment [Line Items]
Assets held-in-trust		1,395

Insurance_Company_Regulatory_R2

Insurance Company Regulatory Requirements - Narrative (Details) (USD $)	3 Months Ended	6 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2013
AGM and AGC [Member]
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Reserves for Contingencies Reassumed	$428
New York [Member] | Assured Guaranty (Europe) and Assured Guaranty Municipal Corp. [Member]
Statutory Accounting Practices [Line Items]
Contingency reserves reassumed, amount		250
New York [Member] | AGM [Member]
Statutory Accounting Practices [Line Items]
Threshold for dividend payments as a percentage of policyholder surplus	10.00%
Threshold for dividend payments, percentage of adjusted net investment income	100.00%
Amount available for distribution, current year	221
Amount available for distribution, next fiscal quarter	40
MARYLAND | AGC [Member]
Statutory Accounting Practices [Line Items]
Threshold for dividend payments as a percentage of policyholder surplus	10.00%
Threshold for dividend payments, percentage of adjusted net investment income	100.00%
Amount available for distribution, next fiscal quarter	16
Reassumed contingency reserves		267
MARYLAND | AGUS [Member] | AGC [Member]
Statutory Accounting Practices [Line Items]
Dividend restrictions on outstanding statutory surplus	90
Bermuda [Member] | Assured Guaranty Re [Member]
Statutory Accounting Practices [Line Items]
Unencumbered assets	588
Dividend Payment Restrictions Schedule, Percentage of Statutory Capital	15.00%
Statutory surplus	271
Dividend restrictions on outstanding statutory surplus	279
Dividend Payment Restrictions Schedule Amount of Statutory Capital	$127
Dividend restrictions on statutory capital and surplus (as a percent)	25.00%

Insurance_Company_Regulatory_R3

Insurance Company Regulatory Requirements - Dividends and Surplus Notes By Insurance Company Subsidiaries (Details) (Affiliated Entity [Member], USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Assured Guaranty LTD [Member] | Assured Guaranty Re [Member]
Statutory Accounting Practices [Line Items]
Dividends paid	$50	$62
AGMH [Member] | AGM [Member]
Statutory Accounting Practices [Line Items]
Dividends paid	66	0
Repayment of surplus notes	25	25
AGUS [Member] | AGC [Member]
Statutory Accounting Practices [Line Items]
Dividends paid	$20	$0

Income_Taxes_Effective_Tax_Rat

Income Taxes - Effective Tax Rate Reconciliation and Pretax Income (Loss) and Revenue by Tax Jurisdiction (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Pre-tax Income Taxes and Revenue [Line Items]
Expected tax provision (benefit) at statutory rates in taxable jurisdictions	$77	$38
Tax-exempt interest	-14	-14
Change in liability for uncertain tax positions	1	1
Other	1	2
Total provision (benefit) for income taxes	65	27
Effective tax rate (as a percent)	24.20%	38.80%
Income (loss) before provision for income taxes	266	69
Revenue	369	195
United States [Member]
Pre-tax Income Taxes and Revenue [Line Items]
Income (loss) before provision for income taxes	223	113
Revenue	300	195
Bermuda [Member]
Pre-tax Income Taxes and Revenue [Line Items]
Income (loss) before provision for income taxes	50	-37
Revenue	73	1
United Kingdom [Member]
Pre-tax Income Taxes and Revenue [Line Items]
Income (loss) before provision for income taxes	-7	-7
Revenue	($4)	($1)

Income_Taxes_Narrative_Details

Income Taxes - Narrative (Details) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Income Taxes [Line Items]
Corporate tax rate	35.00%
Realization assessment period	3 years
Interest and penalties related to uncertain tax positions	$0.50	$1
Accrued interest and penalties, uncertain tax positions	5	4.5	5
Unrecognized tax benefits that would impact effective tax rate	$29	$28	29
United Kingdom [Member]
Income Taxes [Line Items]
Corporate tax rate			21.00%	23.00%
Value added tax rate	20.00%
UNITED KINGDOM
Income Taxes [Line Items]
Corporate tax rate	20.25%	21.50%
Subsequent to April 1, 2015 | United Kingdom [Member]
Income Taxes [Line Items]
Corporate tax rate	20.00%

Reinsurance_and_Other_Monoline2

Reinsurance and Other Monoline Exposures - Effect of Reinsurance on Statement of Operations (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Premiums Written:
Direct	$29		$31
Assumed	3	[1]	-1	[1]
Ceded	0		-24
Net	32		6
Premiums Earned:
Direct	148		140
Assumed	10		11
Ceded	-16		-19
Net earned premiums	142		132
Loss and LAE:
Direct	26		34
Assumed	-7		6
Ceded	-1		1
Loss and LAE	$18		$41
[1]	Negative assumed premiums written were due to change in expected Debt Service schedules.

Reinsurance_and_Other_Monoline3

Reinsurance and Other Monoline Exposures - Exposure by Reinsurer (Details) (USD $)	Mar. 31, 2015
In Millions, unless otherwise specified
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	$21,987	[1]
Second-to- Pay Insured Par Outstanding	17,811	[1]
Assumed Par Outstanding	26,266	[1]
American Overseas Reinsurance Company Limited (f/k/a Ram Re) [Member]
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	6,363	[1]
Second-to- Pay Insured Par Outstanding	0	[1]
Assumed Par Outstanding	30	[1]
Tokio Marine & Nichido Fire Insurance Co., Ltd. (“Tokio”) [Member]
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	5,006	[1],[2]
Second-to- Pay Insured Par Outstanding	0	[1],[2]
Assumed Par Outstanding	0	[1],[2]
Radian [Member]
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	3,984	[1],[3]
Second-to- Pay Insured Par Outstanding	18	[1],[3]
Assumed Par Outstanding	620	[1],[3]
Syncora Guarantee Inc. [Member]
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	3,522	[1]
Second-to- Pay Insured Par Outstanding	1,451	[1]
Assumed Par Outstanding	160	[1]
Mitsui Sumitomo Insurance Co. Ltd. [Member]
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	1,995	[1]
Second-to- Pay Insured Par Outstanding	0	[1]
Assumed Par Outstanding	0	[1]
Aca Financial Guaranty Corp [Member]
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	745	[1]
Second-to- Pay Insured Par Outstanding	1	[1]
Assumed Par Outstanding	0	[1]
Swiss Reinsurance Co. [Member]
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	91	[1]
Second-to- Pay Insured Par Outstanding	0	[1]
Assumed Par Outstanding	0	[1]
Ambac [Member]
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	82	[1]
Second-to- Pay Insured Par Outstanding	4,796	[1]
Assumed Par Outstanding	13,281	[1]
National Public Finance Guarantee Corporation [Member]
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	0	[1],[4]
Second-to- Pay Insured Par Outstanding	6,061	[1],[4]
Assumed Par Outstanding	5,724	[1],[4]
MBIA Inc. [Member]
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	0	[1],[5]
Second-to- Pay Insured Par Outstanding	2,465	[1],[5]
Assumed Par Outstanding	484	[1],[5]
Financial Guaranty Insurance Co [Member]
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	0	[1]
Second-to- Pay Insured Par Outstanding	2,008	[1]
Assumed Par Outstanding	809	[1]
Ambac Assurance Corp. Segregated account [Member]
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	0	[1]
Second-to- Pay Insured Par Outstanding	105	[1]
Assumed Par Outstanding	936	[1]
CIFG Assurance North America Inc. [Member]
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	0	[1]
Second-to- Pay Insured Par Outstanding	102	[1]
Assumed Par Outstanding	4,177	[1]
Other [Member]
Ceded Credit Risk [Line Items]
Ceded Par Outstanding	199	[1]
Second-to- Pay Insured Par Outstanding	804	[1]
Assumed Par Outstanding	$45	[1]
[1]	Includes par related to insured credit derivatives.
[2]	The Company has structural collateral agreements satisfying the triple-A credit requirement of S&P and/or Moody’s.
[3]	(4)On April 1, 2015, AGC consummated the acquisition of Radian Asset and merged Radian Asset with and into AGC, with AGC as the surviving company of the merger.
[4]	(6)NPFGC is rated AA+ by KBRA.
[5]	(7)MBIA includes subsidiaries MBIA Insurance Corp. rated B by S&P and B2 by Moody's and MBIA U.K. Insurance Ltd. rated B by S&P and Ba2 by Moody’s.

Reinsurance_and_Other_Monoline4

Reinsurance and Other Monoline Exposures - Reinsurance and Other Monoline Exposures (Details) (USD $)	Mar. 31, 2015
In Millions, unless otherwise specified
Ceded Credit Risk [Line Items]
Assumed Premium, net of Commissions	$73
Ceded Premium, net of Commissions	-67
Assumed Expected Loss and LAE	-121
Ceded Expected Loss and LAE	97
American Overseas Reinsurance Company Limited (f/k/a Ram Re) [Member]
Ceded Credit Risk [Line Items]
Assumed Premium, net of Commissions	0
Ceded Premium, net of Commissions	-7
Assumed Expected Loss and LAE	0
Ceded Expected Loss and LAE	10
Tokio Marine & Nichido Fire Insurance Co., Ltd. (“Tokio”) [Member]
Ceded Credit Risk [Line Items]
Assumed Premium, net of Commissions	0
Ceded Premium, net of Commissions	-12
Assumed Expected Loss and LAE	0
Ceded Expected Loss and LAE	45
Radian [Member]
Ceded Credit Risk [Line Items]
Assumed Premium, net of Commissions	0
Ceded Premium, net of Commissions	-12
Assumed Expected Loss and LAE	0
Ceded Expected Loss and LAE	18
Syncora Guarantee Inc. [Member]
Ceded Credit Risk [Line Items]
Assumed Premium, net of Commissions	0
Ceded Premium, net of Commissions	-27
Assumed Expected Loss and LAE	0
Ceded Expected Loss and LAE	4
Mitsui Sumitomo Insurance Co. Ltd. [Member]
Ceded Credit Risk [Line Items]
Assumed Premium, net of Commissions	0
Ceded Premium, net of Commissions	-3
Assumed Expected Loss and LAE	0
Ceded Expected Loss and LAE	14
Swiss Reinsurance Co. [Member]
Ceded Credit Risk [Line Items]
Assumed Premium, net of Commissions	0
Ceded Premium, net of Commissions	-2
Assumed Expected Loss and LAE	0
Ceded Expected Loss and LAE	6
Ambac [Member]
Ceded Credit Risk [Line Items]
Assumed Premium, net of Commissions	43
Ceded Premium, net of Commissions	0
Assumed Expected Loss and LAE	-18
Ceded Expected Loss and LAE	0
Ambac Assurance Corp. Segregated account [Member]
Ceded Credit Risk [Line Items]
Assumed Premium, net of Commissions	12
Ceded Premium, net of Commissions	0
Assumed Expected Loss and LAE	-77
Ceded Expected Loss and LAE	0
CIFG Assurance North America Inc. [Member]
Ceded Credit Risk [Line Items]
Assumed Premium, net of Commissions	0
Ceded Premium, net of Commissions	0
Assumed Expected Loss and LAE	-7
Ceded Expected Loss and LAE	0
MBIA Inc. [Member]
Ceded Credit Risk [Line Items]
Assumed Premium, net of Commissions	6
Ceded Premium, net of Commissions	0
Assumed Expected Loss and LAE	-10
Ceded Expected Loss and LAE	0
National Public Finance Guarantee Corporation [Member]
Ceded Credit Risk [Line Items]
Assumed Premium, net of Commissions	6
Ceded Premium, net of Commissions	0
Assumed Expected Loss and LAE	-7
Ceded Expected Loss and LAE	0
Financial Guaranty Insurance Co [Member]
Ceded Credit Risk [Line Items]
Assumed Premium, net of Commissions	4
Ceded Premium, net of Commissions	0
Assumed Expected Loss and LAE	-2
Ceded Expected Loss and LAE	0
Other [Member]
Ceded Credit Risk [Line Items]
Assumed Premium, net of Commissions	2
Ceded Premium, net of Commissions	-4
Assumed Expected Loss and LAE	0
Ceded Expected Loss and LAE	$0

Reinsurance_and_Other_Monoline5

Reinsurance and Other Monoline Exposures - Narrative (Details) (USD $)	3 Months Ended		0 Months Ended	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2015	Jan. 01, 2014	Dec. 31, 2014
Ceded Credit Risk [Line Items]
Reassumed ceded business, par due to commutations	$856,000,000
Fixed-maturity securities		10,182,000,000		11,258,000,000
Assured Guaranty Re [Member]
Ceded Credit Risk [Line Items]
Amounts could be required to pay if third party exercised right to recapture business		81,000,000
AGC [Member]
Ceded Credit Risk [Line Items]
Amounts could be required to pay if third party exercised right to recapture business		48,000,000
Fixed Maturities [Member]
Ceded Credit Risk [Line Items]
Fixed-maturity securities		9,833,000,000		10,491,000,000
Fixed Maturities [Member] | National Public Finance Guarantee Corporation [Member]
Ceded Credit Risk [Line Items]
Fixed-maturity securities		291,000,000
Fixed Maturities [Member] | Ambac [Member]
Ceded Credit Risk [Line Items]
Fixed-maturity securities		247,000,000
Fixed Maturities [Member] | Other [Member]
Ceded Credit Risk [Line Items]
Fixed-maturity securities		32,000,000
Excess of Loss Reinsurance Facility [Member] | AGM, AGC and MAC [Member]
Ceded Credit Risk [Line Items]
Minimum net losses required for attachment of excess of loss reinsurance facility			1,500,000,000
Amount of losses covered under the facility			500,000,000
Reinsurance retention policy, excess retention, amount reinsured			450,000,000
Remaining amount of losses covered under the facility			50,000,000
Premiums paid during the period		$19,000,000		$19,000,000

Commitments_and_Contingencies_

Commitments and Contingencies - Narrative (Details)

3 Months Ended

1 Months Ended

0 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

0 Months Ended

0 Months Ended

0 Months Ended

Mar. 31, 2015

Sep. 30, 2009

Nov. 28, 2011

Nov. 28, 2011

Sep. 25, 2013

28-May-14

Dec. 31, 2008

Dec. 31, 2008

Dec. 31, 2008

Dec. 31, 2008

31-May-10

Apr. 30, 2010

Dec. 31, 2009

Nov. 19, 2012

Nov. 19, 2012

Nov. 19, 2012

Nov. 19, 2012

Jan. 30, 2015

Nov. 28, 2011

Apr. 10, 2015

Apr. 10, 2015

Lawsuit

Governmental Investigations [Member]

LBIE vs. AG Financial Products [Member]

Pending Litigation

Pending Litigation

Pending Litigation

Pending Litigation

Pending Litigation

Pending Litigation

Pending Litigation

Pending Litigation

Pending Litigation

Pending Litigation

Pending Litigation

Pending Litigation

Pending Litigation

Pending Litigation

Settled Litigation [Member]

Positive Outcome of Litigation [Member]

Minimum [Member]

Maximum [Member]

Plaintiff

AG Financial Products Inc. [Member]

LBIE vs. AG Financial Products [Member]

Wells Fargo Bank, N.A., Interpleader Complaint [Member]

Houston Casualty Company Europe Vs Assured Guaranty [Member]

MDL 1950 [Member]

MDL 1950 [Member]

MDL 1950 [Member]

Non-class Action Cases Consolidated with MDL 1950 for Pretrial Proceedings [Member]

Non-class Action Cases Consolidated with MDL 1950 for Pretrial Proceedings [Member]

Non-class Action Cases Consolidated with MDL 1950 for Pretrial Proceedings [Member]

Non-class Action Cases Consolidated with MDL 1950 for Pretrial Proceedings [Member]

LBHI and LBSF vs CPT 283, FSA and AGM [Member]

LBHI and LBSF vs CPT 283, FSA and AGM [Member]

LBHI and LBSF vs CPT 207, FSA and AGM [Member]

LBHI and LBSF vs CPT 207, FSA and AGM [Member]

LBHI and LBSF vs CPT 207, FSA and AGM [Member]

LBIE vs. AG Financial Products [Member]

Positive Outcome of Litigation [Member]

Positive Outcome of Litigation [Member]

Guarantee Obligations [Member]

AG Financial Products Inc. [Member]

AGM [Member]

Radian [Member]

Lawsuit

AGMH [Member]

AGM and AGMH [Member]

AGM and AGMH [Member]

AGM and AGUS [Member]

AGM and AGUS [Member]

AGM and AGUS [Member]

AGM [Member]

AGM [Member]

AGM [Member]

AGM [Member]

AGM [Member]

Lehman Brothers International (Europe) [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Transaction

USD ($)

USD ($)

EUR (€)

Lawsuit

Lawsuit

Proceedings Related to Former Financial Products Business [Member]

Proceedings Related to Former Financial Products Business [Member]

Proceedings Related to Former Financial Products Business [Member]

Proceedings Related to Former Financial Products Business [Member]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Transaction

LBIE vs. AG Financial Products [Member]

LBIE vs. AG Financial Products [Member]

Lawsuit

Lawsuit

Lawsuit

Lawsuit

Lehman Brothers International (Europe) [Member]

Lehman Brothers International (Europe) [Member]

USD ($)

USD ($)

Commitments and Contingencies Legal Proceedings

Minimum number of proceedings for recoveries to have potential material impact

1

Number of credit derivative transactions for which termination payment is alleged to be improperly calculated

9

Gain contingency, number of credit derivative transactions with improperly calculated payments

28

Gain contingency, unrecorded amount

$200,000,000

$500,000,000

Termination payments which LBIE owes to AG Financial Products as per calculation of AG Financial Products

30,000,000

43,800,000

492,555

Loss Contingency, Damages Sought, Value

14,000,000

67,300,000

1,500,000

Litigation Settlement, Amount

20,000,000

Termination payments which AG Financial Products owes to LBIE as per calculation of LBIE

1,400,000,000

Increase in losses as a result of an adverse outcome, minimum

10,000,000

Increase in losses as a result of an adverse outcome, maximum

$20,000,000

Number of putative class action lawsuits filed in federal court

9

4

5

5

5

6

Number of plaintiffs filing consolidated complaints

4

Number of non-class action lawsuits for which dismissal was denied

11

LongTerm_Debt_and_Credit_Facil2

Long-Term Debt and Credit Facilities - Narrative (Details) (USD $)	3 Months Ended		1 Months Ended	0 Months Ended	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Jun. 30, 2003	Apr. 07, 2008	Dec. 31, 2012	Apr. 08, 2005	Jul. 01, 2009	Oct. 25, 2013	Dec. 31, 2014	Jun. 30, 2014
			Trust			Trust
Debt Instrument [Line Items]
Intercompany debt	$0	$0
AGC Trust Preferred Securities [Member]
Debt Instrument [Line Items]
Basis points				2.50%
AGM Trust Preferred Securities [Member]
Debt Instrument [Line Items]
Basis points			2.00%
AGM [Member] | AGM CPS securities [Member]
Debt Instrument [Line Items]
Maximum stock purchase obligation of each custodial trust			50,000,000
Aggregate maximum stock purchase obligation of the custodial trusts			200,000,000
Number of custodial trusts			4
Rate basis for income distributions			one-month LIBOR
Auction interval (in days)			28 days
AGC [Member] | AGM CPS securities [Member]
Debt Instrument [Line Items]
Maximum stock purchase obligation of each custodial trust						200,000,000
Aggregate maximum stock purchase obligation of the custodial trusts						50,000,000
Number of custodial trusts						4
Rate basis for income distributions				one-month LIBOR
Line of Credit [Member] | Strip Coverage Facility [Member] | AGM [Member]
Debt Instrument [Line Items]
Cumulative strip par exposure terminated	1,400,000,000
Commitment amount	1,000,000,000
Covenant terms, additional net worth requirement under reduced borrowing capacity	0
Covenant terms, maximum debt-to-capital ratio							30.00%
Covenant terms, minimum net worth percentage							75.00%
Covenant terms, minimum percentage of aggregate consolidated net income (or loss)	25.00%
Line of Credit [Member] | Revolving Credit Facility [Member] | Wilbur L. Ross [Member]
Debt Instrument [Line Items]
Interest rate, as a percentage of Federal short-term or mid-term interest rate								100.00%
Notes Payable 5.60 Percent [Member] | Notes Payable, Other Payables [Member] | AGMH [Member]
Debt Instrument [Line Items]
Interest rate of debt (as a percent)	5.60%								5.60%
6.25% Notes [Member] | Notes Payable, Other Payables [Member] | AGMH [Member]
Debt Instrument [Line Items]
Interest rate of debt (as a percent)	6.25%								6.25%
QUIBS 6.875 Percent [Member] | Corporate securities [Member] | AGMH [Member]
Debt Instrument [Line Items]
Interest rate of debt (as a percent)	6.88%								6.88%
Senior Notes 7.0 Percent [Member] | Senior Notes [Member] | AGUS [Member]
Debt Instrument [Line Items]
Interest rate of debt (as a percent)	7.00%								7.00%
Senior Notes 5.0 Percent [Member] | Senior Notes [Member] | AGUS [Member]
Debt Instrument [Line Items]
Interest rate of debt (as a percent)	5.00%								5.00%
Intercompany Credit Facility [Member] | Line of Credit [Member] | Revolving Credit Facility [Member] | Wilbur L. Ross [Member] | AGL [Member]
Debt Instrument [Line Items]
Related party, maximum borrowing capacity								225,000,000
Structured Finance [Member] | Financial Guarantee [Member] | AGM [Member]
Debt Instrument [Line Items]
Possible liquidity claims, gross exposure	1,200,000,000
Dexia Credit Local (NY) [Member] | Line of Credit [Member] | Strip Coverage Facility [Member] | AGM [Member]
Debt Instrument [Line Items]
Commitment amount							1,000,000,000			495,000,000
Radian [Member] | AGUS [Member]
Debt Instrument [Line Items]
Intercompany debt	200,000,000
Municipal Assurance Corp [Member] | AGUS [Member]
Debt Instrument [Line Items]
Intercompany debt					$90,000,000

LongTerm_Debt_and_Credit_Facil3

Long-Term Debt and Credit Facilities - Principal and Carrying Amounts of Debt (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Principal	$1,595,000,000	$1,596,000,000
Carrying Value	1,304,000,000	1,303,000,000
AGUS [Member]
Debt Instrument [Line Items]
Principal	850,000,000	850,000,000
Carrying Value	847,000,000	847,000,000
AGMH [Member]
Debt Instrument [Line Items]
Principal	730,000,000	730,000,000
Carrying Value	439,000,000	437,000,000
AGM [Member]
Debt Instrument [Line Items]
Principal	15,000,000	16,000,000
Carrying Value	18,000,000	19,000,000
Senior Notes [Member] | AGUS [Member] | Senior Notes 7.0 Percent [Member]
Debt Instrument [Line Items]
Interest rate of debt (as a percent)	7.00%	7.00%
Principal	200,000,000	200,000,000
Carrying Value	198,000,000	198,000,000
Senior Notes [Member] | AGUS [Member] | Senior Notes 5.0 Percent [Member]
Debt Instrument [Line Items]
Interest rate of debt (as a percent)	5.00%	5.00%
Principal	500,000,000	500,000,000
Carrying Value	499,000,000	499,000,000
Enhanced Junior Subordinated Debentures [Member] | AGUS [Member]
Debt Instrument [Line Items]
Principal	150,000,000	150,000,000
Carrying Value	150,000,000	150,000,000
Corporate securities [Member] | AGMH [Member] | QUIBS 6.875 Percent [Member]
Debt Instrument [Line Items]
Interest rate of debt (as a percent)	6.88%	6.88%
Principal	100,000,000	100,000,000
Carrying Value	68,000,000	68,000,000
Notes Payable, Other Payables [Member] | AGMH [Member] | 6.25% Notes [Member]
Debt Instrument [Line Items]
Interest rate of debt (as a percent)	6.25%	6.25%
Principal	230,000,000	230,000,000
Carrying Value	139,000,000	139,000,000
Notes Payable, Other Payables [Member] | AGMH [Member] | Notes Payable 5.60 Percent [Member]
Debt Instrument [Line Items]
Interest rate of debt (as a percent)	5.60%	5.60%
Principal	100,000,000	100,000,000
Carrying Value	55,000,000	55,000,000
Notes Payable, Other Payables [Member] | AGM [Member]
Debt Instrument [Line Items]
Principal	15,000,000	16,000,000
Carrying Value	18,000,000	19,000,000
Junior Subordinated Debt [Member] | AGMH [Member]
Debt Instrument [Line Items]
Principal	300,000,000	300,000,000
Carrying Value	$177,000,000	$175,000,000

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Basic EPS:
Net income (loss)	$201	$42
Less: Distributed and undistributed income (loss) available to nonvested shareholders	0	0
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, basic	201	42
Basic shares	155.8	182.1
Basic EPS (in dollars per share)	$1.29	$0.23
Diluted EPS:
Plus: Re-allocation of undistributed income (loss) available to nonvested shareholders of AGL and subsidiaries	0	0
Distributed and undistributed income (loss) available to common shareholders of AGL and subsidiaries, diluted	$201	$42
Basic shares	155.8	182.1
Effect of dilutive securities:
Options and restricted stock awards (in shares)	1	1
Diluted shares	156.8	183.1
Diluted EPS (in dollars per share)	$1.28	$0.23
Potentially dilutive securities excluded from computation of EPS because of antidilutive effect	0.7	1.5

Shareholders_Equity_Shares_Rep

Shareholders' Equity - Shares Repurchased (Details) (USD $)	3 Months Ended					12 Months Ended		1 Months Ended	4 Months Ended	28 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	7-May-15	7-May-15	7-May-15	Aug. 06, 2014	8-May-15	6-May-15
Equity, Class of Treasury Stock [Line Items]
Repurchases of common stock	($152,000,000)	($35,000,000)
Common Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Shares repurchased	5,860,291	1,350,443	6,388,187	9,623,309	7,051,842	24,413,781	12,512,759
Repurchases of common stock	-152,000,000	-35,000,000	-152,000,000	-226,000,000	-177,000,000	-590,000,000	-264,000,000
Average price paid (in dollars per share)	$25.87	$25.92	$23.83	$23.47	$25.14	$24.17	$21.12
Authorized repurchase amount											400,000,000
Subsequent Event [Member] | Common Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Shares repurchased								2,058,927	7,919,218	44,845,758
Repurchases of common stock								-56,000,000	-208,000,000	-1,062,000,000
Average price paid (in dollars per share)								$27.36	$26.26	$23.69
Remaining capacity of shares repurchase program												2,000,000
Authorized repurchase amount													$400,000,000

Shareholders_Equity_Changes_in

Shareholders' Equity - Changes in AOCI by Component (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	$370	$160
Other comprehensive income (loss) before reclassifications	11	103
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	16	2
Interest expense	-25	-20
Total (provision) benefit for income taxes	-65	-27
Less: reclassification adjustment for gains (losses) included in net income (loss), net of tax provision (benefit) of $(21), $5 and $(7)	-10	2
Net current period other comprehensive income (loss)	0	104
Balance at end of period	370	264
Reclassification out of Accumulated Other Comprehensive Income [Member]
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	-16	3
Interest expense	-1	0
Total before tax	-17	3
Total (provision) benefit for income taxes	6	-2
Less: reclassification adjustment for gains (losses) included in net income (loss), net of tax provision (benefit) of $(21), $5 and $(7)	-11	1
Net Unrealized Gains (Losses) on Investments with no Other-Than-Temporary Impairment [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	367	178
Other comprehensive income (loss) before reclassifications	18	94
Amounts reclassified from AOCI to:
Net current period other comprehensive income (loss)	5	93
Balance at end of period	372	271
Net Unrealized Gains (Losses) on Investments with no Other-Than-Temporary Impairment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	-20	-2
Interest expense	0	0
Total before tax	-20	-2
Total (provision) benefit for income taxes	7	1
Less: reclassification adjustment for gains (losses) included in net income (loss), net of tax provision (benefit) of $(21), $5 and $(7)	-13	-1
Net Unrealized Gains (Losses) on Investments with Other-Than-Temporary Impairment [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	4	-24
Other comprehensive income (loss) before reclassifications	-2	8
Amounts reclassified from AOCI to:
Net current period other comprehensive income (loss)	1	11
Balance at end of period	5	-13
Net Unrealized Gains (Losses) on Investments with Other-Than-Temporary Impairment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	4	5
Interest expense	0	0
Total before tax	4	5
Total (provision) benefit for income taxes	-1	-2
Less: reclassification adjustment for gains (losses) included in net income (loss), net of tax provision (benefit) of $(21), $5 and $(7)	3	3
Accumulated Translation Adjustment [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	-10	-3
Other comprehensive income (loss) before reclassifications	-5	1
Amounts reclassified from AOCI to:
Net current period other comprehensive income (loss)	-5	1
Balance at end of period	-15	-2
Accumulated Translation Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	0	0
Interest expense	0	0
Total before tax	0	0
Total (provision) benefit for income taxes	0	0
Less: reclassification adjustment for gains (losses) included in net income (loss), net of tax provision (benefit) of $(21), $5 and $(7)	0	0
Cash Flow Hedge [Member]
Changes in Accumulated Other Comprehensive Income [Roll Forward]
Balance at beginning of period	9	9
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from AOCI to:
Net current period other comprehensive income (loss)	-1	-1
Balance at end of period	8	8
Cash Flow Hedge [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Amounts reclassified from AOCI to:
Net realized investment gains (losses)	0	0
Interest expense	-1	0
Total before tax	-1	0
Total (provision) benefit for income taxes	0	-1
Less: reclassification adjustment for gains (losses) included in net income (loss), net of tax provision (benefit) of $(21), $5 and $(7)	($1)	($1)

Subsidiary_Information_Condens

Subsidiary Information - Condensed Consolidating Balance Sheet (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Assets
Total investment portfolio and cash	$11,199	$11,459
Investment in subsidiaries	0	0
Premiums receivable, net of commissions payable	700	729
Ceded unearned premium reserve	365	381
Deferred acquisition costs	120	121
Reinsurance recoverable on unpaid losses	77	78
Credit derivative assets	77	68
Deferred tax asset, net	218	260
Intercompany receivable	0	0
Financial guaranty variable interest entities’ assets, at fair value	1,499	1,402
Other	422	427
Total assets	14,677	14,925
Liabilities and shareholders’ equity
Unearned premium reserve	4,127	4,261
Loss and loss adjustment expense reserve	787	799
Long-term debt	1,304	1,303
Intercompany payable	0	0
Credit derivative liabilities	859	963
Deferred tax liabilities, net	0	0
Financial guaranty variable interest entities’ liabilities, at fair value	1,423	1,419
Other	391	422
Total liabilities	8,891	9,167
Effect on shareholders’ equity (decrease) increase	5,786	5,758
Noncontrolling interest	0	0
Total shareholders' equity	5,786	5,758
Total liabilities and shareholders’ equity	14,677	14,925
Reportable Legal Entities [Member] | Assured Guaranty Ltd. (Parent) [Member]
Assets
Total investment portfolio and cash	47	126
Investment in subsidiaries	5,722	5,612
Premiums receivable, net of commissions payable	0	0
Ceded unearned premium reserve	0	0
Deferred acquisition costs	0	0
Reinsurance recoverable on unpaid losses	0	0
Credit derivative assets	0	0
Deferred tax asset, net	0	0
Intercompany receivable	0	0
Financial guaranty variable interest entities’ assets, at fair value	0	0
Other	21	27
Total assets	5,790	5,765
Liabilities and shareholders’ equity
Unearned premium reserve	0	0
Loss and loss adjustment expense reserve	0	0
Long-term debt	0	0
Intercompany payable	0	0
Credit derivative liabilities	0	0
Deferred tax liabilities, net	0	0
Financial guaranty variable interest entities’ liabilities, at fair value	0	0
Other	4	7
Total liabilities	4	7
Effect on shareholders’ equity (decrease) increase	5,786	5,758
Noncontrolling interest	0	0
Total shareholders' equity	5,786	5,758
Total liabilities and shareholders’ equity	5,790	5,765
Reportable Legal Entities [Member] | AGUS (Issuer) [Member]
Assets
Total investment portfolio and cash	82	204
Investment in subsidiaries	5,087	5,072
Premiums receivable, net of commissions payable	0	0
Ceded unearned premium reserve	0	0
Deferred acquisition costs	0	0
Reinsurance recoverable on unpaid losses	0	0
Credit derivative assets	0	0
Deferred tax asset, net	56	54
Intercompany receivable	200	0
Financial guaranty variable interest entities’ assets, at fair value	0	0
Other	79	77
Total assets	5,504	5,407
Liabilities and shareholders’ equity
Unearned premium reserve	0	0
Loss and loss adjustment expense reserve	0	0
Long-term debt	847	847
Intercompany payable	90	90
Credit derivative liabilities	0	0
Deferred tax liabilities, net	0	0
Financial guaranty variable interest entities’ liabilities, at fair value	0	0
Other	23	9
Total liabilities	960	946
Effect on shareholders’ equity (decrease) increase	4,544	4,461
Noncontrolling interest	0	0
Total shareholders' equity	4,544	4,461
Total liabilities and shareholders’ equity	5,504	5,407
Reportable Legal Entities [Member] | AGMH (Issuer) [Member]
Assets
Total investment portfolio and cash	23	47
Investment in subsidiaries	3,955	3,965
Premiums receivable, net of commissions payable	0	0
Ceded unearned premium reserve	0	0
Deferred acquisition costs	0	0
Reinsurance recoverable on unpaid losses	0	0
Credit derivative assets	0	0
Deferred tax asset, net	0	0
Intercompany receivable	0	0
Financial guaranty variable interest entities’ assets, at fair value	0	0
Other	31	27
Total assets	4,009	4,039
Liabilities and shareholders’ equity
Unearned premium reserve	0	0
Loss and loss adjustment expense reserve	0	0
Long-term debt	439	437
Intercompany payable	0	0
Credit derivative liabilities	0	0
Deferred tax liabilities, net	93	94
Financial guaranty variable interest entities’ liabilities, at fair value	0	0
Other	22	16
Total liabilities	554	547
Effect on shareholders’ equity (decrease) increase	3,455	3,492
Noncontrolling interest	0	0
Total shareholders' equity	3,455	3,492
Total liabilities and shareholders’ equity	4,009	4,039
Reportable Legal Entities [Member] | Other Entities [Member]
Assets
Total investment portfolio and cash	11,347	11,382
Investment in subsidiaries	350	339
Premiums receivable, net of commissions payable	830	864
Ceded unearned premium reserve	1,430	1,469
Deferred acquisition costs	184	186
Reinsurance recoverable on unpaid losses	344	338
Credit derivative assets	262	277
Deferred tax asset, net	251	295
Intercompany receivable	90	90
Financial guaranty variable interest entities’ assets, at fair value	1,499	1,402
Other	522	538
Total assets	17,109	17,180
Liabilities and shareholders’ equity
Unearned premium reserve	5,173	5,328
Loss and loss adjustment expense reserve	1,062	1,066
Long-term debt	18	19
Intercompany payable	500	300
Credit derivative liabilities	1,044	1,172
Deferred tax liabilities, net	0	0
Financial guaranty variable interest entities’ liabilities, at fair value	1,423	1,419
Other	702	764
Total liabilities	9,922	10,068
Effect on shareholders’ equity (decrease) increase	6,837	6,773
Noncontrolling interest	350	339
Total shareholders' equity	7,187	7,112
Total liabilities and shareholders’ equity	17,109	17,180
Consolidating Adjustments [Member]
Assets
Total investment portfolio and cash	-300	-300
Investment in subsidiaries	-15,114	-14,988
Premiums receivable, net of commissions payable	-130	-135
Ceded unearned premium reserve	-1,065	-1,088
Deferred acquisition costs	-64	-65
Reinsurance recoverable on unpaid losses	-267	-260
Credit derivative assets	-185	-209
Deferred tax asset, net	-89	-89
Intercompany receivable	-290	-90
Financial guaranty variable interest entities’ assets, at fair value	0	0
Other	-231	-242
Total assets	-17,735	-17,466
Liabilities and shareholders’ equity
Unearned premium reserve	-1,046	-1,067
Loss and loss adjustment expense reserve	-275	-267
Long-term debt	0	0
Intercompany payable	-590	-390
Credit derivative liabilities	-185	-209
Deferred tax liabilities, net	-93	-94
Financial guaranty variable interest entities’ liabilities, at fair value	0	0
Other	-360	-374
Total liabilities	-2,549	-2,401
Effect on shareholders’ equity (decrease) increase	-14,836	-14,726
Noncontrolling interest	-350	-339
Total shareholders' equity	-15,186	-15,065
Total liabilities and shareholders’ equity	($17,735)	($17,466)

Subsidiary_Information_Condens1

Subsidiary Information - Condensed Consolidating Statement of Operations (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues
Net earned premiums	$142	$132
Net investment income	101	103
Net realized investment gains (losses)	16	2
Net change in fair value of credit derivatives:
Realized gains (losses) and other settlements	21	19
Net unrealized gains (losses)	103	-230
Net change in fair value of credit derivatives	124	-211
Other	-14	169
Total revenues	369	195
Expenses
Loss and LAE	18	41
Amortization of DAC	4	5
Interest expense	25	20
Other operating expenses	56	60
Total expenses	103	126
Income (loss) before income taxes	266	69
Total (provision) benefit for income taxes	-65	-27
Equity in net earnings of subsidiaries	0	0
Net income (loss)	201	42
Less: noncontrolling interest	0	0
Net income (loss)	201	42
Comprehensive income (loss)	201	146
Reportable Legal Entities [Member] | Assured Guaranty Ltd. (Parent) [Member]
Revenues
Net earned premiums	0	0
Net investment income	0	0
Net realized investment gains (losses)	0	0
Net change in fair value of credit derivatives:
Realized gains (losses) and other settlements	0	0
Net unrealized gains (losses)	0	0
Net change in fair value of credit derivatives	0	0
Other	0	0
Total revenues	0	0
Expenses
Loss and LAE	0	0
Amortization of DAC	0	0
Interest expense	0	0
Other operating expenses	8	8
Total expenses	8	8
Income (loss) before income taxes	-8	-8
Total (provision) benefit for income taxes	0	0
Equity in net earnings of subsidiaries	209	50
Net income (loss)	201	42
Less: noncontrolling interest	0	0
Net income (loss)	201	42
Comprehensive income (loss)	201	146
Reportable Legal Entities [Member] | AGUS (Issuer) [Member]
Revenues
Net earned premiums	0	0
Net investment income	0	0
Net realized investment gains (losses)	0	0
Net change in fair value of credit derivatives:
Realized gains (losses) and other settlements	0	0
Net unrealized gains (losses)	0	0
Net change in fair value of credit derivatives	0	0
Other	0	0
Total revenues	0	0
Expenses
Loss and LAE	0	0
Amortization of DAC	0	0
Interest expense	13	7
Other operating expenses	0	0
Total expenses	13	7
Income (loss) before income taxes	-13	-7
Total (provision) benefit for income taxes	5	2
Equity in net earnings of subsidiaries	163	87
Net income (loss)	155	82
Less: noncontrolling interest	0	0
Net income (loss)	155	82
Comprehensive income (loss)	134	165
Reportable Legal Entities [Member] | AGMH (Issuer) [Member]
Revenues
Net earned premiums	0	0
Net investment income	0	0
Net realized investment gains (losses)	0	0
Net change in fair value of credit derivatives:
Realized gains (losses) and other settlements	0	0
Net unrealized gains (losses)	0	0
Net change in fair value of credit derivatives	0	0
Other	0	0
Total revenues	0	0
Expenses
Loss and LAE	0	0
Amortization of DAC	0	0
Interest expense	13	13
Other operating expenses	0	0
Total expenses	13	13
Income (loss) before income taxes	-13	-13
Total (provision) benefit for income taxes	5	5
Equity in net earnings of subsidiaries	92	169
Net income (loss)	84	161
Less: noncontrolling interest	0	0
Net income (loss)	84	161
Comprehensive income (loss)	80	212
Reportable Legal Entities [Member] | Other Entities [Member]
Revenues
Net earned premiums	140	131
Net investment income	104	105
Net realized investment gains (losses)	19	4
Net change in fair value of credit derivatives:
Realized gains (losses) and other settlements	21	19
Net unrealized gains (losses)	103	-230
Net change in fair value of credit derivatives	124	-211
Other	-14	169
Total revenues	373	198
Expenses
Loss and LAE	18	39
Amortization of DAC	6	6
Interest expense	4	5
Other operating expenses	48	53
Total expenses	76	103
Income (loss) before income taxes	297	95
Total (provision) benefit for income taxes	-72	-33
Equity in net earnings of subsidiaries	9	8
Net income (loss)	234	70
Less: noncontrolling interest	9	8
Net income (loss)	225	62
Comprehensive income (loss)	233	258
Consolidating Adjustments [Member]
Revenues
Net earned premiums	2	1
Net investment income	-3	-2
Net realized investment gains (losses)	-3	-2
Net change in fair value of credit derivatives:
Realized gains (losses) and other settlements	0	0
Net unrealized gains (losses)	0	0
Net change in fair value of credit derivatives	0	0
Other	0	0
Total revenues	-4	-3
Expenses
Loss and LAE	0	2
Amortization of DAC	-2	-1
Interest expense	-5	-5
Other operating expenses	0	-1
Total expenses	-7	-5
Income (loss) before income taxes	3	2
Total (provision) benefit for income taxes	-3	-1
Equity in net earnings of subsidiaries	-473	-314
Net income (loss)	-473	-313
Less: noncontrolling interest	-9	-8
Net income (loss)	-464	-305
Comprehensive income (loss)	($447)	($635)

Subsidiary_Information_Condens2

Subsidiary Information - Condensed Consolidating Statement of Cash Flows (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Condensed Cash Flow Statements, Captions [Line Items]
Net cash flows provided by (used in) operating activities	$23,000,000	$101,000,000
Fixed-maturity securities:
Purchases	-448,000,000	-517,000,000
Sales	841,000,000	155,000,000
Maturities	155,000,000	148,000,000
Net sales (purchases) of short-term investments	420,000,000	184,000,000
Net proceeds from financial guaranty variable entities’ assets	30,000,000	286,000,000
Intercompany debt	0	0
Investment in subsidiary	0	0
Other	3,000,000	19,000,000
Net cash flows provided by (used in) investing activities	1,001,000,000	275,000,000
Cash flows from financing activities
Return of capital	0	0
Dividends paid	-19,000,000	-20,000,000
Repurchases of common stock	-152,000,000	-35,000,000
Share activity under option and incentive plans	-5,000,000	0
Net paydowns of financial guaranty variable interest entities’ liabilities	-39,000,000	-281,000,000
Payment of long-term debt	-1,000,000	-6,000,000
Intercompany debt	0	0
Other	4,000,000	0
Net cash flows provided by (used in) financing activities	-212,000,000	-342,000,000
Effect of foreign exchange rate changes	-2,000,000	1,000,000
Increase (decrease) in cash	810,000,000	35,000,000
Cash at beginning of period	75,000,000	184,000,000
Cash at end of period	885,000,000	219,000,000
Reportable Legal Entities [Member] | Assured Guaranty Ltd. (Parent) [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash flows provided by (used in) operating activities	97,000,000	58,000,000
Fixed-maturity securities:
Purchases	0	0
Sales	0	0
Maturities	0	0
Net sales (purchases) of short-term investments	79,000,000	-3,000,000
Net proceeds from financial guaranty variable entities’ assets	0	0
Intercompany debt	0	0
Investment in subsidiary	0	0
Other	0	0
Net cash flows provided by (used in) investing activities	79,000,000	-3,000,000
Cash flows from financing activities
Return of capital	0	0
Dividends paid	-19,000,000	-20,000,000
Repurchases of common stock	-152,000,000	-35,000,000
Share activity under option and incentive plans	-5,000,000	0
Net paydowns of financial guaranty variable interest entities’ liabilities	0	0
Payment of long-term debt	0	0
Intercompany debt	0	0
Other	0
Net cash flows provided by (used in) financing activities	-176,000,000	-55,000,000
Effect of foreign exchange rate changes	0	0
Increase (decrease) in cash	0	0
Cash at beginning of period	0	0
Cash at end of period	0	0
Reportable Legal Entities [Member] | AGUS (Issuer) [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash flows provided by (used in) operating activities	127,000,000	0
Fixed-maturity securities:
Purchases	-46,000,000	-1,000,000
Sales	122,000,000	0
Maturities	4,000,000	0
Net sales (purchases) of short-term investments	43,000,000	0
Net proceeds from financial guaranty variable entities’ assets	0	0
Intercompany debt	-200,000,000	0
Investment in subsidiary	0	0
Other	0	0
Net cash flows provided by (used in) investing activities	-77,000,000	-1,000,000
Cash flows from financing activities
Return of capital	0	0
Dividends paid	-50,000,000	0
Repurchases of common stock	0	0
Share activity under option and incentive plans	0	0
Net paydowns of financial guaranty variable interest entities’ liabilities	0	0
Payment of long-term debt	0	0
Intercompany debt	0	0
Other	0
Net cash flows provided by (used in) financing activities	-50,000,000	0
Effect of foreign exchange rate changes	0	0
Increase (decrease) in cash	0	-1,000,000
Cash at beginning of period	0	67,000,000
Cash at end of period	0	66,000,000
Reportable Legal Entities [Member] | AGMH (Issuer) [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash flows provided by (used in) operating activities	59,000,000	-6,000,000
Fixed-maturity securities:
Purchases	-6,000,000	-3,000,000
Sales	11,000,000	0
Maturities	0	0
Net sales (purchases) of short-term investments	19,000,000	-16,000,000
Net proceeds from financial guaranty variable entities’ assets	0	0
Intercompany debt	0	0
Investment in subsidiary	25,000,000	25,000,000
Other	0	0
Net cash flows provided by (used in) investing activities	49,000,000	6,000,000
Cash flows from financing activities
Return of capital	0	0
Dividends paid	-108,000,000	0
Repurchases of common stock	0	0
Share activity under option and incentive plans	0	0
Net paydowns of financial guaranty variable interest entities’ liabilities	0	0
Payment of long-term debt	0	0
Intercompany debt	0	0
Other	0
Net cash flows provided by (used in) financing activities	-108,000,000	0
Effect of foreign exchange rate changes	0	0
Increase (decrease) in cash	0	0
Cash at beginning of period	4,000,000	0
Cash at end of period	4,000,000	0
Reportable Legal Entities [Member] | Other Entities [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash flows provided by (used in) operating activities	34,000,000	111,000,000
Fixed-maturity securities:
Purchases	-396,000,000	-513,000,000
Sales	708,000,000	155,000,000
Maturities	151,000,000	148,000,000
Net sales (purchases) of short-term investments	279,000,000	203,000,000
Net proceeds from financial guaranty variable entities’ assets	30,000,000	286,000,000
Intercompany debt	0	0
Investment in subsidiary	0	0
Other	3,000,000	19,000,000
Net cash flows provided by (used in) investing activities	775,000,000	298,000,000
Cash flows from financing activities
Return of capital	-25,000,000	-25,000,000
Dividends paid	-136,000,000	-62,000,000
Repurchases of common stock	0	0
Share activity under option and incentive plans	0	0
Net paydowns of financial guaranty variable interest entities’ liabilities	-39,000,000	-281,000,000
Payment of long-term debt	-1,000,000	-6,000,000
Intercompany debt	200,000,000	0
Other	4,000,000
Net cash flows provided by (used in) financing activities	3,000,000	-374,000,000
Effect of foreign exchange rate changes	-2,000,000	1,000,000
Increase (decrease) in cash	810,000,000	36,000,000
Cash at beginning of period	71,000,000	117,000,000
Cash at end of period	881,000,000	153,000,000
Consolidating Adjustments [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash flows provided by (used in) operating activities	-294,000,000	-62,000,000
Fixed-maturity securities:
Purchases	0	0
Sales	0	0
Maturities	0	0
Net sales (purchases) of short-term investments	0	0
Net proceeds from financial guaranty variable entities’ assets	0	0
Intercompany debt	200,000,000	0
Investment in subsidiary	-25,000,000	-25,000,000
Other	0	0
Net cash flows provided by (used in) investing activities	175,000,000	-25,000,000
Cash flows from financing activities
Return of capital	25,000,000	25,000,000
Dividends paid	294,000,000	62,000,000
Repurchases of common stock	0	0
Share activity under option and incentive plans	0	0
Net paydowns of financial guaranty variable interest entities’ liabilities	0	0
Payment of long-term debt	0	0
Intercompany debt	-200,000,000	0
Other	0
Net cash flows provided by (used in) financing activities	119,000,000	87,000,000
Effect of foreign exchange rate changes	0	0
Increase (decrease) in cash	0	0
Cash at beginning of period	0	0
Cash at end of period	$0	$0