MBIA (MBI) 10-Q 6 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 31, 2018
Document Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	MBI
Entity Registrant Name	MBIA INC
Entity Central Index Key	814,585
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		90,690,129
Entity Current Reporting Status	Yes

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents	$ 179	$ 146
Total assets	8,361	9,095
Liabilities:
Total liabilities	7,241	7,670
Commitments and contingencies (Refer to Note 20)
Equity:
Preferred stock, par value $1 per share; authorized shares--10,000,000; issued and outstanding--none	0	0
Common stock, par value $1 per share; authorized shares--400,000,000; issued shares-- 283,625,689 and 283,717,973	284	284
Additional paid-in capital	3,155	3,171
Retained earnings	973	1,095
Accumulated other comprehensive income (loss), net of tax of $7 and $16	(206)	(19)
Treasury stock, at cost-- 192,936,029 and 192,233,526 shares	(3,098)	(3,118)
Total shareholders' equity of MBIA Inc.	1,108	1,413
Preferred stock of subsidiary	12	12
Total equity	1,120	1,425
Total liabilities and equity	8,361	9,095
Non Variable Interest Entity [Member]
Assets
Fixed-maturity securities held as available-for-sale, at fair value (amortized cost $3,562 and $3,728)	3,533	3,712
Investments carried at fair value	231	200
Investments pledged as collateral, at fair value (amortized cost $32 and $147)	30	148
Short-term investments held as available-for-sale, at fair value (amortized cost $411 and $589)	411	589
Other investments (includes investments at fair value of $0 and $4)	1	6
Total investments	4,206	4,655
Cash and cash equivalents	167	122
Premiums receivable	306	369
Deferred acquisition costs	78	95
Insurance loss recoverable	1,542	511
Assets held for sale	0	0
Deferred income taxes, net	0	0
Other assets	125	128
Liabilities:
Unearned premium revenue	609	752
Loss and loss adjustment expense reserves	1,033	979
Long-term debt	2,218	2,121
Medium-term notes (includes financial instruments carried at fair value of $123 and $115)	738	765
Investment agreements	314	337
Derivative liabilities	173	262
Liabilities held for sale	0	0
Other liabilities	196	165
Variable Interest Entity Primary Beneficiary [Member]
Assets
Investments carried at fair value	163	182
Other assets	29	33
Cash	12	24
Investments held-to-maturity, at amortized cost (fair value $901 and $916)	890	890
Loans receivable at fair value	428	1,679
Loan repurchase commitments	415	407
Liabilities:
Variable interest entity notes (includes financial instruments carried at fair value of $709 and $1,069)	$ 1,960	$ 2,289

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Fixed-maturity securities held as available-for-sale, amortized cost	$ 3,852	$ 4,438
Preferred stock, par value	$ 1	$ 1
Preferred stock, authorized shares	10,000,000	10,000,000
Preferred stock, issued	0	0
Preferred stock, outstanding	0	0
Common stock, par value	$ 1	$ 1
Common stock, authorized shares	400,000,000	400,000,000
Common stock, issued shares	283,625,689	283,717,973
Accumulated other comprehensive income (loss), taxes	$ 7	$ 16
Treasury stock, shares	192,936,029	192,233,526
Non Variable Interest Entity [Member]
Fixed-maturity securities held as available-for-sale, amortized cost	$ 3,562	$ 3,728
Investments pledged as collateral, amortized cost	32	147
Short-term investments held as available-for-sale, amortized cost	411	589
Other investments, fair value	0	4
Medium-term notes, financial instruments carried at fair value	123	115
Variable Interest Entity Primary Beneficiary [Member]
Investments held-to-maturity, fair value	901	916
Variable interest entity notes, financial instruments carried at fair value	$ 709	$ 1,069

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Change in fair value of insured derivatives:
Unrealized gains (losses) on insured derivatives			$ 36	$ (10)
Net change in fair value of insured derivatives	$ (1)	$ (1)	(13)	(51)
Net gains (losses) on financial instruments at fair value and foreign exchange	5	(11)	18	(55)
Net investment losses related to other-than-temporary impairments:
Net investment losses related to other-than-temporary impairments	(1)	(71)	(3)	(84)
Net gains (losses) on extinguishment of debt	3	1	3	9
Other net realized gains (losses)	1	(1)	0	36
Total revenues	105	33	190	182
Expenses:
Losses and loss adjustment	46	205	177	469
Interest	52	50	155	148
Total expenses	150	306	477	785
Income (loss) before income taxes	(45)	(273)	(287)	(603)
Provision (benefit) for income taxes	0	(6)	2	965
Net income (loss)	$ (45)	$ (267)	$ (289)	$ (1,568)
Net income (loss) per common share:
Basic	$ (0.5)	$ (2.17)	$ (3.24)	$ (12.38)
Diluted	$ (0.5)	$ (2.17)	$ (3.24)	$ (12.38)
Weighted average number of common shares outstanding:
Basic	89,490,267	122,967,924	89,075,892	126,643,642
Diluted	89,490,267	122,967,924	89,075,892	126,643,642
Non Variable Interest Entity [Member]
Premiums earned:
Scheduled premiums earned	$ 44	$ 26	$ 96	$ 82
Refunding premiums earned	18	27	42	64
Premiums earned (net of ceded premiums of $1, $1, $4 and $4)	62	53	138	146
Net investment income	31	33	96	122
Fees and reimbursements	17	1	23	9
Change in fair value of insured derivatives:
Realized gains (losses) and other settlements on insured derivatives	(5)	(7)	(49)	(41)
Unrealized gains (losses) on insured derivatives	4	6	36	(10)
Net change in fair value of insured derivatives	(1)	(1)	(13)	(51)
Net gains (losses) on financial instruments at fair value and foreign exchange	5	(11)	18	(55)
Net investment losses related to other-than-temporary impairments:
Investment losses related to other-than-temporary impairments	0	(26)	0	(80)
Other-than-temporary impairments recognized in accumulated other comprehensive income (loss)	(1)	(45)	(3)	(4)
Net investment losses related to other-than-temporary impairments	(1)	(71)	(3)	(84)
Net gains (losses) on extinguishment of debt	3	1	3	9
Other net realized gains (losses)	1	(1)	0	36
Expenses:
Losses and loss adjustment	46	205	177	469
Amortization of deferred acquisition costs	9	8	17	23
Operating	18	21	57	82
Interest	52	50	155	148
Variable Interest Entity Primary Beneficiary [Member]
Premiums earned:
Net investment income	9	8	25	20
Change in fair value of insured derivatives:
Net gains (losses) on financial instruments at fair value and foreign exchange	12	21	29	2
Net investment losses related to other-than-temporary impairments:
Other net realized gains (losses)	(33)	0	(126)	28
Expenses:
Operating	3	3	8	8
Interest	$ 22	$ 19	$ 63	$ 55

Consolidated Statements Of Op_2

Consolidated Statements Of Operations (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Financial Guarantee Insurance Segment [Member]
Ceded premiums earned	$ 1	$ 1	$ 4	$ 4

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statements of Comprehensive Income (Loss)
Net income (loss)	$ (45)	$ (267)	$ (289)	$ (1,568)
Unrealized gains (losses) on available-for-sale securities: [Abstract]
Unrealized gains (losses) arising during the period	(4)	16	(61)	20
Provision (benefit) for income taxes	0	7	5	7
Total	(4)	9	(66)	13
Reclassification adjustments for (gains) losses included in net income (loss)	(2)	1	(3)	(4)
Provision (benefit) for income taxes	0	(1)	0	(1)
Total	(2)	2	(3)	(3)
Available-for-sale securities with other-than-temporary impairments: [Abstract]
Other-than-temporary impairments and unrealized gains (losses) arising during the period	25	40	48	6
Provision (benefit) for income taxes	0	2	0	2
Total	25	38	48	4
Reclassification adjustments for (gains) losses included in net income (loss)	2	4	3	6
Provision (benefit) for income taxes	0	1	0	2
Total	2	3	3	4
Foreign currency translation: [Abstract]
Foreign currency translation gains (losses)	0	1	2	145
Provision (benefit) for income taxes	0	(1)	0	20
Total	0	2	2	125
Instrument-specific credit risk of liabilities measured at fair value: [Abstract]
Net gains (losses) of financial instruments at fair value	28	0	(4)	0
Provision (benefit) for income taxes	0	0	0	0
Total	28	0	(4)	0
Total other comprehensive income (loss)	49	54	(20)	143
Comprehensive income (loss)	$ 4	$ (213)	$ (309)	$ (1,425)

Consolidated Statement Of Chang

Consolidated Statement Of Changes In Shareholders' Equity - 9 months ended Sep. 30, 2018 - USD ($) $ in Millions	Total	Preferred Stock [Member]	Total Shareholders' Equity Of MBIA Inc. [Member]	Common Stock [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Total equity balance at Dec. 31, 2017	$ 1,425	$ 12	$ 1,413	$ 284	$ 3,171	$ 1,095	$ (19)	$ (3,118)
Balance (in common stock shares) at Dec. 31, 2017	283,717,973			283,717,973
Balance (in treasury stock shares) at Dec. 31, 2017	(192,233,526)							(192,233,526)
Balance (in preferred stock shares) at Dec. 31, 2017	0	1,315
Cumulative effect of prospective application of new accounting principle | ASU 2016-01 [Member]						164	(164)
Cumulative effect of prospective application of new accounting principle | ASU 2018-02 [Member]	$ 3					3	(3)
Net income (loss)	(289)		(289)			(289)
Total other comprehensive income (loss)	(20)		(20)				(20)
Share-based compensation	5		5	$ 0	5			$ 0
Share-based compensation (in shares)				(92,284)				(18,412)
Treasury shares issued	$ 13		13		(21)			$ 34
Treasury shares issued (in shares)	1,300,000							1,277,620
Treasury shares acquired	$ (14)		(14)					$ (14)
Treasury shares acquired (in shares)								(1,961,711)
Total equity balance at Sep. 30, 2018	$ 1,120	$ 12	$ 1,108	$ 284	$ 3,155	$ 973	$ (206)	$ (3,098)
Balance (in common stock shares) at Sep. 30, 2018	283,625,689			283,625,689
Balance (in treasury stock shares) at Sep. 30, 2018	(192,936,029)							(192,936,029)
Balance (in preferred stock shares) at Sep. 30, 2018	0	1,315

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Premiums, fees and reimbursements received	$ 73	$ 41
Investment income received	162	193
Insured derivative commutations and losses paid	(49)	(41)
Financial guarantee losses and loss adjustment expenses paid	(367)	(744)
Proceeds from recoveries and reinsurance	46	100
Operating and employee related expenses paid	(68)	(103)
Interest paid, net of interest converted to principal	(119)	(139)
Income taxes (paid) received	(1)	0
Net cash provided (used) by operating activities	(323)	(693)
Cash flows from investing activities:
Purchases of available-for-sale investments	(1,684)	(1,146)
Sales of available-for-sale investments	1,647	1,300
Paydowns and maturities of available-for-sale investments	245	392
Purchases of investments at fair value	(142)	(199)
Sales, paydowns and maturities of investments at fair value	162	270
Sales, paydowns and maturities (purchases) of short-term investments, net	269	67
Paydowns and maturities of loans receivable	365	202
Consolidation of variable interest entities	0	18
Deconsolidation of variable interest entities	(7)	0
(Payments) proceeds for derivative settlements	(19)	(58)
Collateral (to) from counterparties	0	4
Capital expenditures	0	(1)
Other investing	0	(23)
Net cash provided (used) by investing activities	836	826
Cash flows from financing activities:
Proceeds from investment agreements	9	13
Principal paydowns of investment agreements	(30)	(57)
Principal paydowns of medium-term notes	(62)	(55)
Proceeds from the MBIA Corp. Financing Facility	0	328
Principal paydowns of variable interest entity notes	(382)	(311)
Purchases of treasury stock	(15)	(98)
Other financing	0	(4)
Net cash provided (used) by financing activities	(480)	(184)
Net increase (decrease) in cash and cash equivalents	33	(51)
Cash and cash equivalents - beginning of period	146	187
Cash and cash equivalents - end of period	179	136
Reconciliation of net income (loss) to net cash provided (used) by operating activities: [Abstract]
Net income (loss)	(289)	(1,568)
Change in: [Abstract]
Premiums receivable	54	34
Deferred acquisition costs	18	22
Unearned premium revenue	(142)	(149)
Loss and loss adjustment expense reserves	50	615
Insurance loss recoverable	(192)	(781)
Accrued interest payable	113	81
Accrued expenses	(10)	(26)
Unrealized (gains) losses on insured derivatives	(36)	10
Net (gains) losses on financial instruments at fair value and foreign exchange	(47)	53
Other net realized (gains) losses	126	(64)
Deferred income tax provision (benefit)	1	961
Interest on variable interest entities, net	14	26
Other operating	17	93
Total adjustments to net income (loss)	(34)	875
Net cash provided (used) by operating activities	(323)	(693)
Supplementary Disclosure of Consolidated Cash Flow Information
Non-cash consideration received from the sale of MBIA UK Insurance Limited	$ 0	$ 332

Business Developments and Risks

Business Developments and Risks and Uncertainties	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Business Developments and Risks and Uncertainties	Note 1: Business Developments and Risks and Uncertainties Summary MBIA Inc., together with its consolidated subsidiaries, (collectively, “MBIA” or the “Company”) operates within the financial guarantee insurance industry. MBIA manages three operating segments: 1) United States (“U.S.”) public finance insurance; 2) corporate; and 3) international and structured finance insurance. The Company’s U.S. public finance insurance business is primarily operated through National Public Finance Guarantee Corporation (“National”) and its international and structu red finance insurance business is primarily operated through MBIA Insurance Corporation and its subsidiaries (“MBIA Corp.”). Refer to “ Note 10: Business Segments ” for further information about the Company’s operating segments. Business Developments Financial Strength R atings In June of 2017, Standard & Poor’s Financial Services LLC (“S&P”) downgraded the financial strength rating of National which made it difficult for National to compete with higher-rated competitors . Theref ore, at that time, National ceased its effort s to actively pursue writing new financial guarantee business. The Company then terminated its agreements with S&P, Kroll Bond Rating Agency (“Kroll”) and Moody’s Investors Services (“Moody’s”) to provide financial strength ratings to MBIA Inc. and certain of its subsidiaries. S&P and Kroll subsequently withdrew all of their ratings. On January 17, 2018, Moody’s downgraded the financial strength rating of National to Baa2 from A3 with a stable outlook, affirmed the financial strength rating of MBIA Corp. at Caa1 with a developing outlook, downgraded MBIA Inc.’s rating to Ba3 with a stable outlook from Ba1 with a negative outlook, and affirmed the financial strength rating of MBIA Mexico S.A. de C.V. (“MBIA Mexico”) at Caa1/B3.mx with a developing outlook. Mo ody’s, at its discretion and in the absence of a contract with the Company, continues to maintain ratings on MBIA Inc. and its subsidiaries. Stock Warrants In April and June of 2018, the holder of certain MBIA Inc. warrants exercised its right to purchase, in total, 11.85 million shares of MBIA Inc. common stock at an exercise price of $9.59 per share. As a result, the Company issued a total of 1.3 million shares of MBIA Inc. common stock to the holder in accordance with the cashless settlement provision of the warrants. As of September 30, 2018 , there were no warrants outstanding. Risks and Uncertainties The Company’s financial statements include estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses. The outcome of certain significant risks and uncertainties could cause the Company to revise its estimates and assumptions or could cause actual results to differ from the Company’s estimates. The discussion below highlights the significant risks and uncertainties that could have a material effect on the Company’s financial statements and business objectives in fut ure periods. U.S. Public Finance Market Conditions National continues to surveil and remediate its existing insured portfolio and will seek opportunities to enhance shareholder value using its strong financial resources, while protecting the interests of all of its policyholders. Certain state and local governments and territory obligors that National insures remain under financial and budgetary stress. This could lead to an increase in defaults by such entities on the payment of their obligations and los ses or impairments on a greater number of National’s insured transactions. National monitors and analyzes these situations and other stressed credits closely, and the overall extent and duration of this stress is uncertain. In particular, the Commonwealt h of Puerto Rico and certain of its instrumentalities (“Puerto Rico”) are experiencing significant fiscal stress and constrained liquidity due to, among other things, Puerto Rico’s structural budget imbalance, the lack of access to the capital markets, a s tagnating local economy, net migration of people out of Puerto Rico and a high debt burden . Although Puerto Rico has tried to address its challenges through various fiscal policies, it continues to experience significant fiscal stress. On January 1, 2018 a nd July 1, 2018, Puerto Rico defaulted on scheduled debt service for National insured bonds and National paid gross claims in the aggregate of $ 276 million. Puerto Rico continues in its efforts to rebuild its infrastructure and to otherwise recover from th e impact of Hurricane Maria in 2017, aided in part by the F ederal E mergency Management A gency and other federal agencies. The extent and duration of such aid is inherently uncertain, and the necessary and greater involvement of the federal government, thro ugh its actions to deliver disaster relief and other support services, in addition to the evolving role of the Financial Oversight and Management Board for Puerto Rico (the “Oversight Board”) and the role of Puerto Rico in its own recovery, heightens polit ical risk in connection with the restructuring of legacy debt. This risk could lead the Oversight Board, Puerto Rico or the federal government to seek to extract greater concessions from creditors based on the uncertainty of Puerto Rico’s long term recover y prospects. In this event, losses at National on select Puerto Rico exposures could increase materially. MBIA Corp. Insured Portfolio MBIA Corp.’s primary objectives are to satisfy all claims by its policyholders and to maximize future recoveries, if any , for its senior lending and other surplus note holders, and then its preferred stock holders. MBIA Corp. is executing this strategy by, among other things, pursuing various actions focused on maximizing the collection of recoveries and by reducing potenti al losses on its insurance exposures. MBIA Corp.’s insured portfolio could deteriorate and result in additional significant loss reserves and claim payments. MBIA Corp.’s ability to meet its obligations is limited by available liquidity and its ability to secure additional liquidity through financing and other transactions. There can be no assurance that MBIA Corp. will be successful in generating sufficient cash to meet its obligations. Zohar and RMBS Recoveries Payment of claims totaling $ 919 million in November of 2015 and January of 2017, on MBIA Corp.’s policies insuring the class A-1 and A-2 notes issued by Zohar CDO 2003-1, Limited (“Zohar I”) and insuring certain notes issued by Zohar II 2005-1, Limited (“Zohar II”), entitles MBIA Corp. to reimburse ment of such amounts plus interest and expenses and/or to exercise certain rights and remedies to seek recovery of such amounts. MBIA Corp. anticipates that the primary source of the recoveries will come from the monetization of the assets of Zohar I and Z ohar II, which include, among other things, loans made to, and equity interests in, companies purportedly controlled by the sponsor and former collateral manager of Zohar I and Zohar II (the “Zohar Sponsor”) (all the assets of Zohar I and Zohar II, the “Zo har Assets”). On March 11, 2018, the then-director of Zohar I and Zohar II placed those funds into voluntary bankruptcy proceedings in federal bankruptcy court in the District of Delaware (the “Zohar Funds Bankruptcy Cases”). On May 21, 2018, the Court gra nted the Zohar funds’ motion to approve a settlement (the “Zohar Bankruptcy Settlement”) which established a process by which the debtor funds, through an independent director and a chief restructuring officer, will work with the original sponsor of the fu nds to monetize the Zohar Assets and repay creditors, including MBIA Corp. In addition, the Zohar Bankruptcy Settlement provides for a stay of all pending litigation between the parties for a minimum of fifteen months. Subsequent to the Zohar Bankruptcy Se ttlement, the Company deconsolidated Zohar I and Zohar II as variable interest entities (“VIEs” or “VIE”) and, as of September 30, 2018 , salvage and subrogation recoveries related to Zohar I and Zohar II are reported within “Insurance loss recoverable” o n the Company’s consolidated balance sheet. Refer to “Note 4: Variable Interest Entities” for additional information about the deconsolidation of the Zohar funds. Notwithstanding the Zohar Bankruptcy Settlement, there can be no assurance that the value of the Zohar Assets will be sufficient to permit MBIA Corp. to recover all or substantially all of the payments it made on Zohar I and Zohar II. MBIA Corp. also projects to collect excess spread from insured residential mortgage-backed securities (“RMBS”), and to recover proceeds from Credit Suisse Securities (USA) LLC, DLJ Mortgage Capital, Inc. and Select Portfolio Servicing Inc. (collectively, “Credit Suisse”) arising from its failure to repurchase ineligible loans that were included in a Credit Suisse sp onsored RMBS transaction. However, the amount and timing of these collections and recoveries are uncertain. Failure to collect a substantial amount of its expected recoveries could impede MBIA Corp.’s ability to make payments when due on other policies. M BIA Corp. believes that if the New York State Department of Financial Services (“NYSDFS”) concludes at any time that MBIA Insurance Corporation will not be able to pay its policyholder claims, the NYSDFS would likely put MBIA Insurance Corporation into a r ehabilitation or liquidation proceeding under Article 74 of the New York Insurance Law and/or take such other actions as the NYSDFS may deem necessary to protect the interests of MBIA Insurance Corporation’s policyholders. The determination to commence suc h a proceeding or take other such actions is within the exclusive control of the NYSDFS. Given the separation of MBIA Inc. and MBIA Corp. as distinct legal entities, the absence of any cross defaults between the entities and the lack of reliance by MBIA I nc. on MBIA Corp. for the receipt of dividends, the Company does not believe that a rehabilitation or liquidation proceeding with respect to MBIA Insurance Corporation would have any significant liquidity impact on MBIA Inc. or result in a liquidation or s imilar proceeding of MBIA Mexico. Such a proceeding could have material adverse consequences for MBIA Corp., including the termination of insured credit default swaps (“CDS”) and other derivative contracts for which counterparties may assert market-based c laims, the acceleration of debt obligations issued by affiliates and insured by MBIA Corp., the loss of control of MBIA Insurance Corporation to a rehabilitator or liquidator, and unplanned costs. Refer to “ Note 5: Loss and Loss Adjustment Expense Reserves ” for additional information about MBI A Corp.’s r ecoveries . Corporate Liquidity Subsequent to September 30, 2018, National declared and paid a dividend of $ 108 million to its ultimate parent, MBIA Inc. Also, subsequent to September 30, 201 8 , National purchased from MBIA Inc., certain MBIA Inc. 5.700 % Senior Notes due 2034 and certain MBIA Inc. 7.000 % Debentures due 2025 that were previously repurchased by MBIA Inc. and had not been retired, resulting in an increase to MBIA Inc.’s liquidity of $ 41 million . Based on the Company’s projections of National’s dividends, additional anticipated releases under its tax sharing agreement and related tax escrow account (“ Tax Escrow Account ”) , and other cash inflows, the Company expects that MBIA Inc. will have sufficient cash to satisfy its debt service and general corporate needs. However, MBIA Inc. continues to have liquidity risk which could be triggered by deterioration in the performance of invested assets, interruption of or reduction in dividends or tax payments received from operating subsidiarie s, impaired access to the capital markets, as well as other factors which are not anticipated at this time. Furthermore, failure by MBIA Inc. to settle liabilities that are also insured by MBIA Corp. could result in claims on MBIA Corp.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Significant Accounting Policies	Note 2: Significant Accounting Policies The Company has disclosed its significant accounting policies in “ Note 2: Significant Accounting Policies ” in the Notes to Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 . The following significant accounting policies provide an update to those included in the Company’s Annual Report on Form 10-K. Basis of Presentation The accompanying unaudited consolidated financial statements have been prepared in accordance with the instructions to Fo rm 10-Q and Article 10 of Regulation S-X and, accordingly, do not include all of the information and disclosures required by accounting principles generally accepted in the United States of America (“ GAAP ”) for annual periods. These statements should be re ad in conjunction with the consolidated financial statements and notes thereto included in the Annual Report on Form 10-K for the year ended December 31, 2017 . The accompanying consolidated financial statements have not been audited by an independent re gistered public accounting firm in accordance with the standards of the Public Company Accounting Oversight Board (U.S.), but in the opinion of management such financial statements include all adjustments, consisting only of normal recurring adjustments, n ecessary for the fair statement of the Company’s consolidated financial position and results of operations. All material intercompany balances and transactions have been eliminated. The preparation of financial statements requires management to make estima tes and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actu al results could differ from those estimates. As additional information becomes available or actual amounts become determinable, the recorded estimates are revised and reflected in operating results. The results of operations for the three and nine months ended September 30, 2018 may not be indicative of the results that may be expected for the year ending December 31, 2018 . The December 31, 2017 consolidated balance sheet was derived from audited financial statements, but does not include all disclosures requi red by GAAP for annual periods. Certain amounts have been reclassified in the prior year’s financial statements to conform to the current presentation. This includes a change in the classification of certain cash receipts and cash payments on the Company’s consolidated statement of cash flows as required under Accounting Standards Update (“ASU”) 2016- 15 , “ Statement of Cash Flows (Topic 230 )”. This classification change a ffected “Interest paid, net of interest converted to principal”, in operating cash flows , and “Principal paydowns of investment agreements ” and “Principal paydowns of medium-term notes”, in financing cash flows, on the Company’s consolidated statement of cash flows for the prior period. Such reclassifications did not materially impact total r evenues, expenses, assets, liabilities, shareholders’ equity, operating cash flows, investing cash flows, or financing cash flows for all periods presented . During the third quarter of 2018, the Company corrected an error related to the second quarter of 2 018 of $ 3 million and an error related to the first quarter of 2017 of $ 3 million, which, in aggregate, reduced the third quarter of 2018’s net loss by $ 6 million. The first quarter of 2017 error related to a gain of the extinguishment of debt and the second quarter of 2018 error related to a benefit on losses and loss adjustment expense. The Company evaluated the materiality of these errors in accordance with Securities and Exch ange Commission (“SEC”) Staff Accounting Bulletin No. 99, Materiality, and SEC Staff Accounting Bulletin No. 108, Considering the Effects of Prior Year Misstatements When Quantifying Misstatements in Current Year Financial Statements, and concluded that th ese errors, individually and in the aggregate, were immaterial to the three months ended September 30, 2018 and the prior periods to which these errors relate.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Recent Accounting Pronouncements	Note 3: Recent Accounting Pronouncements Recently Adopted Accounting Standards Revenue from Contracts with Customers (Topic 606) (ASU 2014-09) and Deferral of the Effective Date (ASU 201 5 - 14 ) In May of 2014, the Financial Accounting Standards Board (“FASB”) issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 amends the accounting guidance for recognizing revenue for the transfer of goods or services from contracts with customers unless those contracts are within the scope of other accounting stan dards. ASU 2014-09 does not apply to financial guarantee insurance contracts within the scope of Topic 944, “Financial Services — Insurance.” In August of 2015, the FASB issued ASU 2015-14, “Revenue from Contracts with Customers (Topic 606) — Deferral of t he Effective Date. ” ASU 2015-14 defers the effective date of ASU 2014-09 to interim and annual periods beginning January 1, 2018, and is applied on a retrospective or modified retrospective basis. The Company adopted ASU 2014-09 in the first quarter of 201 8 and the adoption of ASU 2014-09 did not affect the Company’s consolidated financial statements. Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (ASU 2016-01) In January of 2016, t he FASB issued ASU 2016-01, “Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities.” ASU 2016-01 requires certain equity investments other than those accounted for under the equity method of accounting or result in consolidation of the investee to be measured at fair value with changes in fair value recognized in net income, and permits an entity to measure equity investments that do not have readily determinable fair values at cost less a ny impairment plus or minus adjustments for certain changes in observable prices. An entity is also required to evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale (“AFS”) debt securities in combination with th e entity’s other deferred tax assets. ASU 2016-01 requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability that results from a change in the instrument-specific credit risk for financial liabilities that the entity has elected to measure at fair value in accordance with the fair value option for financial instruments. ASU 2016-01 wa s effective for interim and annual periods beginning January 1, 2018 . As such, the Company reclasse d a loss of $ 162 million from retained earnings to accumulated other comprehensive income (“AOCI”) related to the instrument-specific credit risk portion of financial liabilities measured at fair value in accordance with the fair value option. In addition, the Company reclassed net unrealized gains of $ 2 million from AOCI to retained earnings related to equity investments. As of September 30, 2018 and December 31, 2017 , the Company had a full valuation allowance against its deferred tax asset. Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income (ASU 2018-02) In February of 2018, the FASB issued ASU 2018-02, “Income Statement – Reporting Comprehensive Income ( Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” ASU 2018-02 permits, but does not require, the reclassification of the income tax effects of the Tax Cuts and Jobs Act (the “Act”) from AOCI to retained earni ngs. ASU 2018-02 is effective for interim and annual periods beginning after December 15, 2018. Early adoption of ASU 2018-02 is permitted and is applied in the period of adoption or retroactively to each period in which the effect of the change in the U.S . federal corporate income tax rate in the Act is recognized. The Company adopted ASU 2018-02 in the first quarter of 2018. As such, the Company reclassed income taxes of $ 3 million from AOCI to retained earnings. The Company’s accounting policy related to releasing income tax effects that are lodged in AOCI is on a portfolio approach basis. The Company has not adopted any other new accounting pronouncements that had a material impact on its consolidated financial statements. Recent Accounting Developments Leases (Topic 842) (ASU 2016-02) In February of 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)” , that amends the accounting guidance for leasing transactions. ASU 2016-02 requires a lessee to classify lease contracts as finance or operating lease s, and to recognize assets and liabilities for the rights and obligations created by leasing transactions with lease terms more than twelve months. ASU 2016-02 substantially retains the criteria for classifying leasing transactions as finance or operating leases. For finance leases, a lessee recognizes a right-of-use asset and a lease liability initially measured at the present value of the lease payments, and recognizes interest expense on the lease liability separately from the amortization of the right-o f-use asset. For operating leases, a lessee recognizes a right-of-use asset and a lease liability initially measured at the present value of the lease payments, and recognizes lease expense on a straight-line basis. ASU 2016-02 is effective for interim and annual periods beginning January 1, 2019 with early adoption permitted, and is applied on a modified retrospective basis. The Company is currently evaluating its lease commitments and expects an increase in its total assets and total liabilities on its con solidated balance sheet reflecting the recognition of its right-of-use asset and lease liability, respectively. The gross up of the assets and liabilities is expected to have no impact on the Company’s statement of operations. Refer to “Note 13: Commitments and Continge ncies” for information about the Company’s lease commitments. Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13) In June of 2016, the FASB issued ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 requires financing receivables and other financial assets measured at amortized cost to be presented at the net amount expected to be collected by recording an allowanc e for credit losses with changes in the allowance recorded as credit loss expense or reversal of credit loss expense based on management’s current estimate of expected credit losses each period. ASU 2016-13 does not apply to credit losses on financial guar antee insurance contracts within the scope of Topic 944, “Financial Services-Insurance.” ASU 2016-13 also requires impairment relating to credit losses on AFS debt securities to be presented through an allowance for credit losses with changes in the allowa nce recorded in the period of the change as credit loss expense or reversal of credit loss expense. Any impairment amount not recorded through an allowance for credit losses on AFS debt securities is recorded through other comprehensive income. ASU 2016-13 is effective for interim and annual periods beginning January 1, 2020 with early adoption permitted beginning January 1, 2019. ASU 2016-13 is applied on a modified retrospective basis except that prospective application is applied to AFS debt securities w ith other-than-temporary impairments (“OTTI”) recognized before the date of adoption. The Company is evaluating the impact of adopting ASU 2016-13 . Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Va lue Measurement (ASU 2018-13) In August of 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement.” ASU 2018-13 modifies the disclosure requirements on fair value measurements. ASU 2018-13 is effective for interim and annual periods beginning January 1, 2020 with early adoption permitted to remove or modify disclosures upon issuance of the standard and delay adoption of the additional disclosures until th e effective date. Upon the effective date, certain amendments should be applied prospectively, while others are to be applied retrospectively to all periods presented. The Company is evaluating the impact of adopting ASU 2018-13. Since the amendments of AS U 2018-13 only impact disclosure requirements, the Company does not expect the adoption of ASU 2018-13 to have an impact on its consolidated financial statements.

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2018
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Variable Interest Entities	Note 4: Variable Interest Entities Through MBIA’s international and structured finance insurance segment, the Company provides credit protection to issuers of obligations that may involve issuer-sponsored special purpose entities (“SPEs”). An SPE may be considered a VIE to the extent the SPE’s total equity at risk is not sufficient to permit the SPE to finance its activities without additional subordinated financial support or its equity investors lack any one of the following characteristics : (i) the power to direct the activities of the SPE that most significantly impact the entity’s economic performance or (ii) the obligation to absorb the expected losses of the entity or the right to receive the expected residual returns of the entity. A holder of a variable interest or interests in a VIE is required to assess whether it has a controlling financial interest, and thus is required to consolidate the entity as primary beneficiary. An assessment of a controlling financial interest identifies the prim ary beneficiary as the variable interest holder that has both of the following characteristics : (i) the power to direct the activities of the VIE that most significantly impact the entity’s economic performance and (ii) the obligation to absorb losses of t he entity or the right to receive benefits from the entity that could potentially be significant to the VIE. The primary beneficiary is required to consolidate the VIE. An ongoing reassessment of controlling financial interest is required to be performed b ased on any substantive changes in facts and circumstances involving the VIE and its variable interests. The Company evaluates issuer-sponsored SPEs initially to determine if an entity is a VIE, and is required to reconsider its initial determination if ce rtain events occur. For all entities determined to be VIEs, MBIA performs an ongoing reassessment to determine whether its guarantee to provide credit protection on obligations issued by VIEs provides the Company with a controlling financial interest. Base d on its ongoing reassessment of controlling financial interest, the Company determines whether a VIE is required to be consolidated or deconsolidated. The Company makes its determination for consolidation based on a qualitative assessment of the purpose a nd design of a VIE, the terms and characteristics of variable interests of an entity, and the risks a VIE is designed to create and pass through to holders of variable interests. The Company generally provides credit protection on obligations issued by VIE s, and holds certain contractual rights according to the purpose and design of a VIE. The Company may have the ability to direct certain activities of a VIE depending on facts and circumstances, including the occurrence of certain contingent events, and th ese activities may be considered the activities of a VIE that most significantly impact the entity’s economic performance. The Company generally considers its guarantee of principal and interest payments of insured obligations, given nonperformance by a VI E, to be an obligation to absorb losses of the entity that could potentially be significant to the VIE. At the time the Company determines it has the ability to direct the activities of a VIE that most significantly impact the economic performance of the e ntity based on facts and circumstances, MBIA is deemed to have a controlling financial interest in the VIE and is required to consolidate the entity as primary beneficiary. The Company performs an ongoing reassessment of controlling financial interest that may result in consolidation or deconsolidation of any VIE. Consolidated VIEs The carrying amounts of assets and liabilities of consolidated VIEs were $ 1.9 billion and $ 2.0 billion, respectively, as of September 30, 2018 , and $ 3.2 billion and $ 2.3 billion, respectively , as of December 31, 2017 . The carrying amounts of assets and liabilities are presented separately in “Assets of consolidated variable interest entities” and “Liabilities of consolidated variable interest entities” on the Co mpany’s consolidated balance sheets. VIEs are consolidated or deconsolidated based on an ongoing reassessment of controlling financial interest, when events occur or circumstances arise, and whether the ability to exercise rights that constitute power to d irect activities of any VIEs are present according to the design and characteristics of these entities. In May of 2018, the Court overseeing the Zohar Funds Bankruptcy Cases approved the Zohar Bankruptcy Settlement, which concerns two entities that the Com pany had consolidated as VIEs. As a result, in the second quarter of 2018, the Company deconsolidated these two VIEs and recorded a $93 million loss within “Other net realized gains (losses)” under “Revenues of consolidated variable interest entities” on t he Company’s consolidated statement of operations. The loss resulted from the difference between the fair value of the VIE assets that were deconsolidated and the Company’s current estimate of salvage and subrogation recoveries from those VIEs under insura nce accounting. Refer to “Note 1: Business Developments and Risks and Uncertainties” for further information about the Zohar Bankruptcy Settlement. In the third quarter of 2018, three VIEs were deconsolidated. No additional VIEs were consolidated during the nine months ended September 30, 2018 . Holders of insured obli gations of issuer-sponsored VIEs related to the Company’s international and structured finance insurance segment do not have recourse to the general assets of MBIA. In the event of nonpayment of an insured obligation issued by a consolidated VIE, the Compa ny is obligated to pay principal and interest, when due, on the respective insured obligation only. The Company’s exposure to consolidated VIEs is limited to the credit protection provided on insured obligations and any additional variable interests held b y MBIA. N o n c o n s o l i d a t e d V I Es T h e f ol l owin g t able s p r e s en t t h e t o t a l a ss e t s o f n o n c on s oli d a t e d V I E s i n whi ch t h e Co m p a n y ho l d s a v a r iab l e i n t e r e s t as o f September 30, 2018 a n d December 31, 2017 , through its insurance operations. T h e f o l lowi n g t abl e s al so p r e s en t t h e Co m pan y ’ s m a x i m u m e x po s u re t o l o ss f o r n o n c on s olid a t e d V I Es and carrying v a lu e s o f t h e a s s e t s a n d liab i li t ie s f o r i t s in t e r e st s in t he se V I Es a s o f September 30, 2018 an d December 31, 2017 . The maximum exposure to loss as a result of MBIA’s variable interests in VIEs is represented by insurance in force. Insurance in force is the maximum future payments of principal and interest which may be required under commitments to make payments on insured obligations issued by nonconsolidated VIEs. T h e Co m pa n y ha s agg r eg a t e d non c o n s o lida t e d V I Es b a s e d o n t he und e r l y in g c r e di t e x p o s u r e o f t h e in s u r e d ob l iga t ion . T h e na t u re o f t h e C o m p a n y ’ s v a r i a bl e in t e r e s t s i n non c on s o l ida t ed V I Es i s r el a t e d t o f in a n c ia l gua r an t ee s an d an y i n v e s t m en t s i n o b liga t io n s i ss ue d by non c o n s o lida t e d V I Es. September 30, 2018 Carrying Value of Assets Carrying Value of Liabilities Loss and Loss Maximum Unearned Adjustment VIE Exposure Premiums Insurance Loss Premium Expense In millions Assets to Loss Investments (1) Receivable (2) Recoverable (3) Revenue (4) Reserves (5) Insurance: Global structured finance: Mortgage-backed residential $ 5,879 $ 3,251 $ 18 $ 20 $ 143 $ 18 $ 356 Mortgage-backed commercial 131 59 - - - - - Consumer asset-backed 4,514 586 - 2 1 1 10 Corporate asset-backed 3,854 1,377 - 9 839 11 10 Total global structured finance 14,378 5,273 18 31 983 30 376 Global public finance 15,058 2,296 - 9 - 12 - Total insurance $ 29,436 $ 7,569 $ 18 $ 40 $ 983 $ 42 $ 376 __________ (1) - Reported within "Investments" on MBIA's consolidated balance sheets. (2) - Reported within "Premiums receivable" on MBIA's consolidated balance sheets. (3) - Reported within "Insurance loss recoverable" on MBIA's consolidated balance sheets. (4) - Reported within "Unearned premium revenue" on MBIA's consolidated balance sheets. (5) - Reported within "Loss and loss adjustment expense reserves" on MBIA's consolidated balance sheets. December 31, 2017 Carrying Value of Assets Carrying Value of Liabilities Loss and Loss Maximum Unearned Adjustment VIE Exposure Premiums Insurance Loss Premium Expense In millions Assets to Loss Investments (1) Receivable (2) Recoverable (3) Revenue (4) Reserves (5) Insurance: Global structured finance: Mortgage-backed residential $ 7,295 $ 3,741 $ 19 $ 22 $ 172 $ 20 $ 396 Mortgage-backed commercial 216 94 - - - - - Consumer asset-backed 5,010 981 - 4 1 3 10 Corporate asset-backed 2,418 1,645 - 13 - 14 - Total global structured finance 14,939 6,461 19 39 173 37 406 Global public finance 15,568 2,524 - 10 - 14 - Total insurance $ 30,507 $ 8,985 $ 19 $ 49 $ 173 $ 51 $ 406 __________ (1) - Reported within "Investments" on MBIA's consolidated balance sheets. (2) - Reported within "Premiums receivable" on MBIA's consolidated balance sheets. (3) - Reported within "Insurance loss recoverable" on MBIA's consolidated balance sheets. (4) - Reported within "Unearned premium revenue" on MBIA's consolidated balance sheets. (5) - Reported within "Loss and loss adjustment expense reserves" on MBIA's consolidated balance sheets.

Loss and Loss Adjustment Expens

Loss and Loss Adjustment Expense Reserves	9 Months Ended
	Sep. 30, 2018
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Loss and Loss Adjustment Expense Reserves	Note 5: Loss and Loss Adjustment Expense Reserves U.S. Public Finance Insurance U.S. public finance insur ed transactions consist of municipal bonds, including tax-exempt and taxable indebtedness of U.S. political subdivisions, as well as utilities, airports, health care institutions, higher educational facilities, student loan issuers, housing authorities and other similar agencies and obligations issued by private entities that finance projects that serve a substantial public purpose. The Company estimates future losses by using probability-weighted cas h flow scenarios that are customized to each insured transaction. Future loss estimates consider debt service due for each insured transaction, which includes par outstanding and interest due, as well as recoveries for such payments, if any. Gross par outs tanding for c apital appreciation bonds represents the par amount at the time of issuance of the insurance policy . Certain local governments remain under financial and budgetary stress and a few have filed for protection under Title 11 of the United States Code (the “Bankruptcy Code”) , or have entered into state statutory proceedings established to assist municipalities in managing through periods of severe fiscal stress. In the case of Puerto Rico, certain credits that the Company insures have filed petitio ns for covered instrumentalities under Title III of the Puerto Rico Oversight, Management and Economic Stability Act (“PROMESA”), which incorporates by reference provisions from the Bankruptcy Code. This could lead to an increase in defaults by such entiti es on the payment of their obligations and losses or impairments i n greater amounts on the Company’s insured transactions. The filing for protection under the Bankruptcy Code or entering state statutory proceedings does not necessarily result in a default or indicate that an ultimate loss will occur . Refer to “Note 1: Business Development and Risk and Uncertainties”, for further information on the Company’s Puerto Rico exposures. International and Structured Finance Insurance T he international and structur ed finance insurance segment’s case basis reserves and insurance loss recoveries recorded in accordance with GAAP do not include estimates for a polic y insuring a credit derivative or on financial guarantee VIEs that are eliminated in consolidation . The p o lic y insuring a credit derivative contract is accounted for as a derivative and is carried at fair value in the Company’s consolidated financial statements under GAAP. The fair value of an insured credit derivative contract is influenced by a variety of market and transaction-specific factors that may be unrelated to potential future claim payments under the Company’s insurance policies. In the absence of credit impairments on an insured credit derivative contract or the early t ermination of such contract at a loss, the cumulative unrealize d losses recorded from this contract should reverse before or at the maturity of the contract . As the Company’s insured credit derivative has similar terms, conditions, risks, and economic prof iles to its financial guarantee insurance policies, the Company evaluates it for impairment , under statutory accounting principles, in the same way that it estimates loss and loss adjustment expense (“ LAE ”) for its financial guarantee policies. Refer to “ Note 8: Derivative Instruments ” for a further discussion of the Company’s use of derivatives and their impact on the Company’s consolidated financial statements. RMBS Case Basis Reserves (Financial Guarantees) The Company’s RMBS reserves and recoveries relate to financi al guarantee insurance policies , excluding those on consolidated VIEs . The Company’s first-lien RMBS case basis reserves primarily relate to RMBS backed by alternative A-paper and subprime mortgage loans. The Company’s second-lien RMBS case basis reserves relate to RMBS backed by home equity lines of credit and closed-end second mortgages. The Company calculated RMBS case basis reserves as of September 30, 2018 for both first and second-lien RMBS transactions using a process called the “Roll Rate Methodol ogy .” The Roll Rate Methodology is a multi-step process using database s of loan level information, proprietary internal cash flow model s , and commercially available model s to estimate potential losses and recoveries on insured bonds. Refer to “Note 6: Loss and Loss Adjustment Expense Reserves” in the Notes to Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017, for additional information regarding the Company’s Roll Rate Methodology for its RMBS case basis reserves. The Company monitors portfolio performance on a monthly basis against projected performance, reviewing delinquencies, r oll r ates, and prepayment rates (including voluntary and involuntary). However, loan performance remains difficult to predict and losses may exceed expectations. In the event of a material deviation in actual performance from projected performance, the Company would increase or decrease the case basis reserves accordingly. RMBS Recoveries The Company primar ily records two types of recoveries related to insured RMBS exposures: excess spread that is generated from the trust structures in the insured transactions; and second-lien “put-back” claims related to those mortgage loans whose inclusion in an insured se curitization failed to comply with representations and warranties (“ineligible loans”). Excess Spread Excess spread within insured RMBS securitizations is the difference between interest inflows on mortgage loan collateral and interest outflows on the insu red RMBS notes. The aggregate amount of excess spread depends on the future loss trends, which include future delinquency trends, average time to charge-off/liquidate delinquent loans, the future spread between Prime and the LIBOR interest rates, and borro wer refinancing behavior (which may be affected by changes in the interest rate environment) that results in voluntary prepayments. Minor deviations in loss trends and voluntary prepayments may substantially impact the amounts collected from excess spread. Excess spread also includes subsequent recoveries on previously charged-off loans associated with insured second-lien RMBS securitizations. Second-lien Put-Back Claims Related to Ineligible Loans The Company has settled the majority of the Company’s put-b ack claims relating to the inclusion of ineligible loans in securitizations it insured . Only its claims against Credit Suisse remain outstanding. Credit Suisse has challenged the Company’s assessment of the ineligibility of individual mortgage loans and th e dispute is the subject of litigation for which there is no assurance that the Company will prevail. The Company’s settlement amounts on its prior put-back claims have been consistent with the put-back recoveries that had been included in the Company’s fi nancial statements at the times preceding the settlements . Based on the Company’s assessment of the strength of its contractual put-back rights against Credit Suisse, as well as on its prior settlements with other sellers/servicers and success of other mon olines’ put-back settlements, the Company believes it will prevail in enforcing its contractual rights and that it is entitled to collect the full amount of its incurred losses. Refer to “Note 6: Loss and Loss Adjustment Expense Reserves” in the Notes to Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017, and “ Note 13: Commitments and Contingencies ” for further information about the Company’s litigation with Credit Suisse. CDO Reserves and Recoveries The Company also has lo ss and LAE reserves on certain transactions within its collateralized debt obligations (“ CDO ”) portfolio, primarily its multi-sector CDO asset class that was insured in the form of financial guarantee policies. MBIA’s insured multi-s ector CDOs are transactions that include a variety of collateral ranging from corporate bonds to structured finance assets (which includes , but are not limited to , RMBS-related collateral, multi-sector and corporate CDOs). Zohar Recoveries MBIA Corp. will seek to recover the payment s it made (plus interest and expenses) with respect to Zohar I and Zohar II . MBIA Corp. anticipates that the primary source of the recover ies w ill come from the monetization of the Zohar A ssets as anticipated in the Zohar Bankrup tcy Settlement . Since the second quarter of 2018, th e Company no longer consolidates the Zohar funds as VIEs and estimated recoveries from Zohar I and Zohar II are included in “Insurance loss recoverable” on the Company’s consolidated balance sheets. As of M a r c h 3 1 , 2 0 1 8 a n d December 31, 2017 , the fair value of the assets of Zohar I and Zohar II are included in “Loans receivable at fair value” under “Assets of consolidated variable interest entities” on the Company’s consolidated balance sheets. Refer to “N ote 1: Business Developments and Risks and Uncertainties” for additional information about the estimated Zohar recoveries. Notwithstanding the procedures agreed to in the Zohar Bankruptcy Settlement, there can be no assurance that the value of the Zohar Assets will be sufficient to permit MBIA Corp. to recover all or substantially all of the payments it made on Zohar I and Zohar II. Failure to recover a substantial amount of such payments could impede MBIA Corp.’s ability to make payments when due on other policies. MBIA Corp. believes that if the NYSDFS concludes at any time that MBIA Insurance Corporation will not be able to pay its policyholder claims, the NYSDFS would likely put MBIA Insurance Corpo ration into a rehabilitation or liquidation proceeding under Article 74 of the New York Insurance Law and/or take such other actions as the NYSDFS may deem necessary to protect the interests of MBIA Insurance Corporation’s policyholders. The determination to commence such a proceeding or take other such actions is within the exclusive control of the NYSDFS. Summary of Loss and LAE Reserves and Recoveries The Company’s loss and LAE reserves and recoveries before consolidated VIE eliminations, along with a mounts that were eliminated as a result of consolidat ed VIEs, which are included in the Company’s consolidated balance sheets as of September 30, 2018 and December 31, 2017 are presented in the following table: As of September 30, 2018 As of December 31, 2017 In millions Balance Sheet Line Item Balance Sheet Line Item Insurance loss recoverable Loss and LAE reserves Insurance loss recoverable Loss and LAE reserves U.S. Public Finance Insurance $ 554 $ 634 $ 333 $ 512 International and Structured Finance Insurance: Before VIE eliminations (1) 1,457 628 1,478 710 VIE eliminations (1) (469) (229) (1,300) (243) Total international and structured finance insurance 988 399 178 467 Total $ 1,542 $ 1,033 $ 511 $ 979 _________________ (1) - Includes loan repurchase commitments of $415 million and $407 million as of September 30, 2018 and December 31, 2017, respectively. Changes in Loss and LAE Reserves The Company’s recoveries are based on either salvage rights, the rights conferred to MBIA through the transactional documents (inclusive of the insurance agreements), or subrogation rights embedded within financial guarantee insurance policies. Expected salvage and subrogation recoveries, as well as recoveries from other remediation efforts, r educe the Company’s claim liability. Once a claim payment has been made, the claim liability has been satisfied and MBIA’s right to recovery is no longer considered an offset to future expected claim payments, the right to recovery is recorded as a salv age asset. The amount of recoveries recorded by the Company is limited to paid claims plus the present value of projected estimated future claim payments. As claim payments are made, the recorded amount of potential recoveries may exceed the remaining amount of the claim liability for a given policy. The gross claim lia bility and gross potential recoveries reflect the elimination of claim liabilities and potential recoveries related to VIEs consolidated by the Company. The following table present s changes in the Company’s loss and LAE reserves for the nine months ended September 30, 2018 . Changes in loss reserves attributable to the accretion of the claim liability discount, changes in discount rates, changes in amount and timing of estimated claim payments and recoveries, changes in assumptions and changes in LAE reserv es are recorded in “Losses and loss adjustment” expenses in the Company’s consolidated statements of operations. As of September 30, 2018 , the weighted average risk-free rate used to discount the Company’s loss reserves (claim liability) was 3.03 % . LAE reserves are generally expected to be settled within a one-year period and are not discounted . As of September 30, 2018 and December 31, 2017 , the Company’s gross loss and LAE reserves included $ 74 million and $ 66 million, respectively, related to LAE. In millions Changes in Loss and LAE Reserves for the Nine Months Ended September 30, 2018 Gross Loss Gross Loss and LAE Accretion Changes in and LAE Reserves as of of Claim Changes in Unearned Changes in Reserves as of December 31, Loss Liability Discount Changes in Premium LAE September 30, 2017 Payments Discount Rates Assumptions Revenue Reserves Other (1) 2018 $ 979 $ (344) $ 18 $ 25 $ 336 $ 12 $ 8 $ (1) $ 1,033 ____________ (1) - Primarily changes in amount and timing of payments. The increase in the Company’s gross loss and LAE reserves during the nine months ended September 30, 2018 was primarily related to certain Puerto Rico exposures and changes in the interest rate environment, partially offset by decrease s in insured RMBS and other insured financial guarantee transactions. Changes in Insurance Loss Recoverable and Recoveries on Unpaid Losses C u rr en t pe r io d ch a nge s i n th e C o m pan y ’ s est i mat e o f p o tent i a l r e c o v e r i e s ma y be r e c o r de d a s a n in s u r an c e l oss r e c ove r a bl e as s et , net t e d a g ain s t th e g r os s l o s s an d L A E r e se r v e l i abi l i t y , or bo t h . The following table present s changes in the Company’s insurance loss recoverable and changes in recoveries on unpaid losses reported within the Company’s claim liability for the nine months ended September 30, 2018 . Changes in insurance loss recoverable attributable to the accretion of the discount on the recoverable, changes in discount rates, changes in amount and timing of estimated collections, changes in assumptions and changes in LAE recoveries are recorded in “Losses and loss adjustment” expenses in the Company’s consolidated s tatements of operations. Changes in Insurance Loss Recoverable and Recoveries on Unpaid Losses for the Nine Months Ended September 30, 2018 Gross Gross Reserve Reserve as of Accretion Changes in Changes in as of December 31, Collections of Discount Changes in LAE September 30, In millions 2017 for Cases Recoveries Rates Assumptions Recoveries Other (1) 2018 Insurance loss recoverable $ 511 $ (42) $ 14 $ (29) $ 1,084 (2) $ - $ 4 $ 1,542 Recoveries on unpaid losses (3) 35 - 1 (1) (8) (6) - 21 Total $ 546 $ (42) $ 15 $ (30) $ 1,076 $ (6) $ 4 $ 1,563 ____________ (1) - Primarily changes in amount and timing of collections. (2) - Includes amounts which have been paid and are expected to be recovered in the future. (3) - As of September 30, 2018 and December 31, 2017, excludes Puerto Rico recoveries which have been netted against reserves. The inc rease in the Company’s insurance loss recoverable reflected in the preceding table was primarily due to the re-establishment of recoveries for Zohar I and Zohar II upon deconsolidation during the second quarter of 2018 and to a lesser extent, amounts related to the anticipated recovery of claims paid to certain Puerto Rico credits . Loss and LAE Activity For the three months ended September 30, 2018 , losses and LAE incurred primarily related to increases in actual and expected payments on Puerto Rico exposures . For the nine months ended September 30, 2018 , losses and LAE incurred primarily related to increases in actual and expected payments on Puerto Rico exposures, partially offset by a decrease on actual and expected payments on insured RMBS transactions . For the three months ended September 30, 2017 , losses and LAE incurred primarily related to in creases in actual and expected payments on certain Puerto Rico exposures and decreases in projected collections from mortgage insurance included in the Company’s excess spread within its second-lien RMBS transactions from the settle ment of litigation regarding insurance coverage involving Old Republic Insura nce Corporation, Bank of America, N.A. and the Bank of New York Mellon . For the nine months ended September 30, 2017 , incurred loss and LAE activity related to increa ses in actual and expected payments on certain Puerto Rico exposures and insured first-lien RMBS securitizations and a decrease in actual and projected collection s from mortgage insurance included in the Company’s excess spread within its second-lien RMBS transactions from the settlement of litigation regarding insurance coverage involving Old Republic Insurance Corporation, Bank of America, N.A. and the Bank of New York Mellon . Costs associated with remediating insured obligations assigned to the Company’s surveillance categories are recorded as LAE and are included in “Losses and loss adjustment” expenses on the Company’s consolidated statements of operations. For the three months ended September 30, 2018 and 2017 , gross LAE related to remediating insured obligati ons were $ 6 million . For the nine months ended September 30, 2018 and 2017 , gross LAE related to remediating insured obligations were $ 28 million and $ 33 million, respectively. Surveillance Categories T h e f ol l owin g t abl e p r o v ide s in f o rm a t i o n a bou t t h e f i nan c ia l gu a r a n t e e s an d r el a t e d c la i m li a bili t y i n c lude d i n ea ch of M B I A ’ s s u rv e i llan ce c a t ego r ie s a s o f September 30, 2018 : Surveillance Categories Caution Caution Caution List List List Classified $ in millions Low Medium High List Total Number of policies 56 20 - 243 319 Number of issues (1) 16 6 - 109 131 Remaining weighted average contract period (in years) 7.2 8.0 - 9.7 9.0 Gross insured contractual payments outstanding: (2) Principal $ 1,933 $ 262 $ - $ 5,465 $ 7,660 Interest 2,314 131 - 5,443 7,888 Total $ 4,247 $ 393 $ - $ 10,908 $ 15,548 Gross Claim Liability (3) $ - $ - $ - $ 1,076 $ 1,076 Less: Gross Potential Recoveries (4) - - - 2,058 2,058 Discount, net (5) - - - (483) (483) Net claim liability (recoverable) $ - $ - $ - $ (499) $ (499) Unearned premium revenue $ 6 $ 4 $ - $ 65 $ 75 Reinsurance recoverable on paid and unpaid losses (6) $ 23 __________ (1) - An “issue” represents the aggregate of financial guarantee policies that share the same revenue source for purposes of making debt service payments on the insured debt. (2) - Represents contractual principal and interest payments due by the issuer of the obligations insured by MBIA. (3) - The gross claim liability with respect to Puerto Rico exposures are net of expected recoveries for policies in a net payable position. (4) - Gross potential recoveries with respect to certain Puerto Rico exposures are net of the claim liability for policies in a net recoverable position. (5) - Represents discount related to Gross Claim Liability and Gross Potential Recoveries. (6) - Included in "Other assets" on the Company's consolidated balance sheets. T h e f ol l owin g t abl e p r o v ide s in f o rm a t i o n a bou t t h e f i nan c ia l gu a r a n t e e s an d r el a t e d c la i m li a bili t y i n c lude d i n ea ch of M B I A ’ s s u rv e i llan ce c a t ego r ie s a s o f December 31, 2017 : Surveillance Categories Caution Caution Caution List List List Classified $ in millions Low Medium High List Total Number of policies 89 5 1 280 375 Number of issues (1) 20 4 1 119 144 Remaining weighted average contract period (in years) 7.4 4.3 8.7 9.7 8.9 Gross insured contractual payments outstanding: (2) Principal $ 2,764 $ 13 $ 104 $ 6,083 $ 8,964 Interest 2,676 3 46 5,756 8,481 Total $ 5,440 $ 16 $ 150 $ 11,839 $ 17,445 Gross Claim Liability (3) $ - $ - $ - $ 1,082 $ 1,082 Less: Gross Potential Recoveries (4) - - - 782 782 Discount, net (5) - - - (178) (178) Net claim liability (recoverable) $ - $ - $ - $ 478 $ 478 Unearned premium revenue $ 9 $ - $ 4 $ 77 $ 90 Reinsurance recoverable on paid and unpaid losses (6) $ 17 __________ (1) - An “issue” represents the aggregate of financial guarantee policies that share the same revenue source for purposes of making debt service payments on the insured debt. (2) - Represents contractual principal and interest payments due by the issuer of the obligations insured by MBIA. (3) - The gross claim liability with respect to Puerto Rico exposures are net of expected recoveries for policies in a net payable position. (4) - Gross potential recoveries with respect to certain Puerto Rico exposures are net of the claim liability for policies in a net recoverable position. (5) - Represents discount related to Gross Claim Liability and Gross Potential Recoveries. (6) - Included in "Other assets" on the Company's consolidated balance sheets. The change from a net claim liability as of December 31, 2017 to a net claim recoverable as of September 30, 2018 is due to the fact that the Company no longer consolidates the Zohar funds as VIEs and estimated recoveries from Zohar I and Zohar II are included in “Insurance loss recoverable” on the Company’s consolidated balance sheet. As of March 31, 2018 and December 31, 2017 , gross potential recoveries exclude the recoveries of Zohar I a nd Zohar II that are included in “Loans receivable at fair value” which are presented in “Assets of consolidated variable interest entities” on the Company’s consolidated balance sheets .

Fair Value Of Financial Instrum

Fair Value Of Financial Instruments	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Fair Value Measurement	Note 6: Fair Value of Financial Instruments Fair Value Measurement Financial Assets Financial assets held by the Company primarily consist of investments in debt securities. Substantially all of the Company’s investments are priced by independent third parties, including pricing services and brokers. Typically, the Company receives one pricing service v alue or broker quote for each instrument, which represents a non-binding indication of value. The Company, along with its third-party portfolio manager, reviews the assumptions, inp uts and methodologies used by pricing services and brokers to obtain reason able assurance that the prices used in its valuations reflect fair value. When the Company and its third-party portfolio manager believe a third-party quotation differs significantl y from its internally developed expectation of fair value, whether higher or lower, the Company reviews its data or assumptions with the provider. This review includes comparing significant assumptions such as prepayment speeds, default ratios, forward yie ld curves, credit spreads and other significant quantitative inputs to internal assumptions, and working with the price provider to reconcile the differences. The price provider may subsequently provide an updated price. In the event that the price provide r does not update its price, and the Company still does not agree with the price provided, its third-party portfolio manager will obtain a price from another third-party provider or use an internally developed price which it believes represents the fair va lue of the investment. The fair values of investments for which internal prices were used were not significant to the aggregate fair value of the Company’s investment portfolio as of September 30, 2018 or December 31, 2017 . All challenges to third-par ty prices are reviewed by staff of the Company as well as its third-party portfolio manager with relevant expertise to ensure reasonableness of assumptions. A pricing analysis is reviewed and approved by the Company’s v aluation c ommittee. Financial Liabili ties (excluding derivative liabilities) Financial liabilities, excluding derivative liabilities, issued by the Company primarily consist of debt issued for general corporate purposes within its corporate segment, medium-term notes (“ MTNs ”), investment agre ements and debt issued by consolidated VIEs. The majority of the financial liabilities that the Company has elected to fair value or that require fair value reporting or disclosures are valued based on the estimated value of the underlying collateral, the Company’s or a third-party’s estimate of discounted cash flow model estimates, or quoted market values for similar products. These valuations include adjustments for expected nonperformance risk of the Company. Derivative Liabilities The Company’s derivati ve liabilities are primarily interest rate swaps and an insured credit derivative. The Company’s insured credit derivative contract is a non-traded structured credit derivative transaction and since it is highly customized , there is generally no observable market for th is derivative . T he Company estimates its fair value in a hypothetical market based on an internal model that incorporates market or estimated prices of similar securities that are obtained for all collateral within a transaction, the present value of the market-implied potential loss and nonperformance risk. The Company reviews its valuation model results on a quarterly basis to assess the appropriateness of the assumptions and results in light of current market activity and conditions. This r eview is performed by internal staff with relevant expertise. Internal Review Process All significant financial assets and liabilities are reviewed by the valuation committee to ensure compliance with the Company’s policies and risk procedures in the deve lopment of fair values of financial assets and liabilities. Th e valuation committee review s , among other things, key assumptions used for internally developed prices, significant changes in sources and uses of inputs, including changes in model approaches, and any adjustments from third-party inputs or prices to internally developed inputs or prices. The committee also review s any significant impairment or improvements in fair values of the financial instruments from prior periods. The committee is comprise d of senior finance team members with relevant experience in the financial instruments their committee is responsible for. T he committee document s its agreement with the fair value measurements reported in the Company’s consolidated financial statements. V aluation Techniques Valuation techniques for financial instruments measured at fair value are described below. Fixed-Maturity Securities Held as Available-For-Sale, Investments Carried at Fair Value , Investments Pledged as Collateral and S hort-term I nvestm ents These investments include investments in U.S. Treasury and government agencies, state and municipal bonds, foreign governments, corporate obligations, mortgage-backed securities (“MB S ”) , asset-backed securities , money market securities, and perpetual debt and equity securities. These investments are generally valued based on recently executed transaction prices or quoted market prices. When quoted market prices are not available, fair value is generally determined using quoted prices of similar investments or a valuation model based on observable and unobservable inputs. Inputs vary depending on the type of investment. Observable inputs include contractual cash flows, interest rate yield curves, CDS spreads, prepayment and volatility scores, dive rsity scores, cross-currency basis index spreads, and credit spreads for structures similar to the financial instrument in terms of issuer, maturity and seniority. Unobservable inputs include cash flow projections and the value of any credit enhancement. T he investment in the fixed - income fund was measured at fair value by applying the net asset value per share practical expedient. The investment in the fixed - income fund may be redeemed on a quarterly basis with prior redemption notification of ninety days subject to withdrawal limitations. The investment is required to be held for a minimum of twelve months, and any subsequent quarterly redemption is limited to 25% of the investment or a complete redemption over four consecutive quarters in the amounts of 2 5%, 33%, 50%, and 100% of the remaining investment balance as of the first, second, third and fourth consecutive quarters, respectively. Investments based on quoted market prices of identical investments in active markets are classified as Level 1 of the fair value hierarchy. Level 1 investments generally consist of U.S. Treasury and government agency, money market securities and perpetual debt and equity securities . Quoted market prices of investments in less active marke ts, as well as investments which are valued based on other than quoted prices for which the inputs are observable, such as interest rate yield curves, are categorized in Level 2 of the fair value hierarchy. Investments that contain significant inputs that are not observable are categorized as Level 3. Cash and Cash Equivalents The carrying amounts of cash and cash equivalents approximate fair value due to the short-term nature and credit worthiness of these instruments and are categorized in Level 1 of the fair value hierarchy. Loans Receivable at Fair Value Loans receivable at fair value are comprised of loans held by consolidated VIEs consisting of residential mortgage and corporate loans. Fair values of residential mortgage loans are determined using quot ed prices for MBS issued by the respective VIE and adjusted for the fair values of the financial guarantees provided by MBIA Corp. on the related MBS. The fair values of the financial guarantees consider expected claim payments, net of recoveries, under MB IA Corp.’s policies. Fair values of corporate l oans , which are to privately held companies, are based on methodologies that generally use comparable EBITDA multiples and the most current available EBITDAs . Loan Repurchase Commitments Loan repurchase commi tments are obligations owed by the sellers/servicers of mortgage loans to MBIA as reimbursement of paid claims. Loan repurchase commitments are assets of the consolidated VIEs. This asset represents the rights of MBIA against the sellers/servicers for brea ches of representations and warranties that the securitized residential mortgage loans sold to the trust to comply with stated underwriting guidelines and for the sellers/servicers to cure, replace, or repurchase mortgage loans. Fair value measurements of loan repurchase commitments represent the amounts owed by the sellers/servicers to MBIA as reimbursement of paid claims. Loan repurchase commitments are not securities and no quoted prices or comparable market transaction information are observable or avai lable. Fair values of loan repurchase commitments are determined using discounted cash flow techniques and are categorized in Level 3 of the fair value hierarchy . Other Assets A VIE consolidated by the Company ha s entered into a deriva tive instrument consisting of a cross currency swap. The c ross currency swap is entered into to manage the variability in cash flows resulting from fluctuations in foreign currency rates. The fair value of the VIE derivative is determined based on inputs from unobservable cash flows projection of the derivative, discounted using observable discount rates. As the significant inputs are unobservable, the derivative contract is categorized in Level 3 of the fair value hierarchy. Other assets also include receivables represen ting the right to receive reimbursement payments on claim payments expected to be made on certain insured VIE liabilities due to risk mitigating transactions with third parties executed to effectively defease, or, in-substance commute the Company’s exposur e on its financial guarantee policies. The right to receive reimbursement payments is based on the value of the Company’s financial guarantee determined using the cash flow model. The fair value of the financial guarantee primarily contains unobservable in puts and is categorized in Level 3 of the fair value hierarchy. Medium- t erm Notes at Fair Value The Company has elected to measure certain MTNs at fair value on a recurring basis . The fair values of certain MTNs are based on quoted market prices provided by third-party sources, where available. When quoted market prices are not available, the Company applies a matrix pricing grid to determine fair value based on the quoted market prices received for similar instruments and considering the MTNs’ stated matu rity and interest rate. Nonperformance risk is included in the quoted market prices and the matrix pricing grid. MTNs are categorized in Level 3 of the fair value hierarchy. Variable Interest Entity Notes The fair values of VIE notes are determined based on recently executed transaction prices or quoted prices where observable. When position-specific quoted prices are not observable, fair values are based on quoted prices of similar securities. Fair values based on quoted prices of similar securitie s may be adjusted for factors unique to the securities, including any credit enhancement. Observable inputs include interest rate yield curves and bond spreads of similar securities. Unobservable inputs include the value of any credit enhancement. VIE note s are categorized in Level 2 or Level 3 of the fair value hierarchy based on the lowest level input that is significant to the fair value measurement in its entirety. Derivatives The corporate segment has entered into derivative transactions primarily con sisting of interest rate swaps. Fair values of over-the-counter derivatives are determined using valuation models based on observable inputs, nonperformance risk of the Company and nonperformance risk of the counterparties. Observable and market-based inpu ts include interest rate yields, credit spreads and volatilities. These derivatives are categorized in Level 2 or Level 3 of the fair value hierarchy based on the lowest level input that is significant to the fair value measurement in its entirety. Derivat ives—Insurance The derivative contracts insured by the Company cannot be legally traded and generally do not have observable market prices. The Company determines the fair values of insured credit derivatives using valuation models based on observable inputs and considering nonperformance risk of the Company . Negotiated settlements are also considered to validate the valuation models and to reflect assumptions the Company believes market participant s would use . Valuation Model Overv iew T he Company uses an internally developed Direct Price Model to value its insured credit derivative that incorporate s market prices or estimated prices of similar securities that are obtained for all collateral within a transaction, the present value of the market-implied potential losses, and nonperformance risk. The valuation of the insured credit derivative includes the impact of its credit standing. The insured credit derivative is categorized in Level 3 of the fair value hierarchy based on unobserva ble inputs that are significant to the fair value measurement in its entirety. The Company a lso has other derivative liabilities as a result of a commutation that occurred in 2014. The fair value of the derivative is determined using a discounted cash flow model. Key inputs include unobservable cash flows projected over the expected term of the derivative. As the significant inputs are un observable, the derivative contract is categorized in Level 3 of the fair value hierarchy. Other Liabilities Stock warra nts issued by the Company are valued using the Black-Scholes model and are recorded at fair value. Inputs into the warrant valuation include the Company’s stock price, the strike price of the warrant, time to expiration, a volatility parameter, interest ra tes, and dividend data. As all significant inputs are market-based and observable, warrants are categorized in Level 2 of the fair value hierarchy. As of September 30, 2018 , there were no warrants outstanding. Other payable relates to certain contingent consideration. The fair value of the liability is based on the cash flow methodologies using observable and unobservable inputs. Unobservable inputs include invested asset balances and asset management fees that are significant to the fair value estimate a nd the liability is categorized in Level 3 of the fair value hierarchy. Significant Unobservable Inputs The following tables provide quantitative information regarding the significant unobservable inputs used by the Company for assets and liabilities measu red at fair value on a recurring basis as of September 30, 2018 and December 31, 2017 . Fair Value as of Range September 30, (Weighted In millions 2018 Valuation Techniques Unobservable Input Average) Assets of consolidated VIEs: Loans receivable at fair value $ 428 Market prices adjusted for financial Impact of financial guarantee (1) -18% - 63% (-5%) guarantees provided to VIE obligations Loan repurchase commitments 415 Discounted cash flow Recovery rates (2) Breach rates (2) Liabilities of consolidated VIEs: Variable interest entity notes 382 Market prices of VIE assets adjusted for Impact of financial guarantee 0% - 65% (40%) financial guarantees provided Credit derivative liabilities: CMBS 27 Direct Price Model Nonperformance risk 54% - 54% (54%) Other derivative liabilities 7 Discounted cash flow Cash flows $0 - $49 ($25) (3) ____________ (1) - Negative percentage represents financial guarantee policies in a receivable position. (2) - Recovery rates and breach rates include estimates about potential variations in the outcome of litigation with a counterparty. (3) - Midpoint of cash flows are used for the weighted average. Fair Value as of Range December 31, (Weighted In millions 2017 Valuation Techniques Unobservable Input Average) Assets of consolidated VIEs: Loans receivable at fair value $ 1,679 Market prices adjusted for financial Impact of financial guarantee (1) -25% - 35% (-2%) guarantees provided to VIE obligations Multiples of EBITDA Multiples (2) Loan repurchase commitments 407 Discounted cash flow Recovery rates (3) Breach rates (3) Liabilities of consolidated VIEs: Variable interest entity notes 406 Market prices of VIE assets Impact of financial guarantee 0% - 60% (36%) adjusted for financial guarantees provided Credit derivative liabilities: CMBS 63 Direct Price Model Nonperformance risk 54% - 54% (54%) Other derivative liabilities 4 Discounted cash flow Cash flows $0 - $49 ($25) (4) ____________ (1) - Negative percentage represents financial guarantee policies in a receivable position. (2) - Unobservable inputs are primarily based on comparable companies' EBITDA multiples. (3) - Recovery rates and breach rates include estimates about potential variations in the outcome of litigation with a counterparty. (4) - Midpoint of cash flows are used for the weighted average. Sensitivity of Significant Unobservable Inputs As of September 30, 2018 , t he significant unobservable input used in the fair value measurement of the Company’s loans receivable at fair value of consolidated VIEs is the impact of the financial guarantee . The fair value of loans receivable is calculated by subtracting the value of the financial guarantee from the market value of VIE liabilities . The value of a financial guarantee is estimated by the Company as the present value of expected cash payments , net of recoveries, under the policy. As the value of the financial guarantee provided by the Company under the insurance policy increases, there is a lower expected cash flow on the underlying loans receivable of the VIE. This results in a lower fair value of the loans receivable in relation to the obligations of the VIE. In addition to the impact of the financial guarantee, as of December 31, 2017, t he fair value of loans receivable also includes certain methodologies using multiples of EBITDA . Multiples a re external factors that are considered when determining the fair values of corporate loans. These loans are to privately held companies for which the Company has limited information. The significant unobservable inputs used in the fair value measurement of the Company’s loan repurchase commitments of consolidated VIEs are the recovery rates and breach rates. Recovery rates reflect the estimates of future cash flows reduced for litigation delays and risks and/or potential financial distress of the sellers/ servicers. The estimated recoveries of the loan repurchase commitments may differ from the actual recoveries that may be received in the future. Breach rates represent the rate at which mortgages fail to comply with stated representations and warranties of the sellers/servicers. Significant increases or decreases in the recovery rates and the breach rates would result in significantly higher or lower fair values of the loan repurchase commitments, respectively. Additionally, changes in the legal environment and the ability of the counterparties to pay would impact the recovery rate assumptions, which could significantly impact the fair value measurement. Any significant challenges by the counterparties to the Company’s determination of breaches of representa tions and warranties could have a material adverse impact on the fair value measurement. Recovery rates and breach rates are determined independently. Changes in one input will not necessarily have any impact on the other input. The significant unobservabl e input used in the fair value measurement of the Company’s VIE notes of consolidated VIEs is the impact of the financial guarantee. The fair value of VIE notes is calculated by adding the value of the financial guarantee to the market value of VIE assets. The value of a financial guarantee is estimated by the Company as the present value of expected cash payments under the policy. As the value of the guarantee provided by the Company to the obligations issued by the VIE increases, the credit support adds v alue to the liabilities of the VIE. This results in an increase in the fair value of the liabilities of the VIE. The significant unobservable input used in the fair value measurement of MBIA Corp.’s commercial mortgage-backed securities (“CMBS”) credit der ivative, which is valued using the Direct Price Model, is nonperformance risk. The nonperformance risk is an assumption of MBIA Corp.’s own ability to pay and whether MBIA Corp. will have the necessary resources to pay the obligations as they come due. Any significant increase or decrease in MBIA Corp.’s nonperformance risk would result in a decrease or increase in the fair value of the derivative liabilities, respectively. The significant unobservable input used in the fair value measurement of MBIA Corp.’ s other derivatives, which are valued using a discounted cash flow m odel , is the estimates of future cash flows discounted using market rates and CDS spreads. Any significant increase or decrease in future cash flows would result in a n increase or decrease in the fair value of the derivative liabilit y , respectively . Fair Value Measurements The following tables present the fair value of the Company’s assets (including short-term investments) and liabilities measured and reported at fair value on a recurring basis as of September 30, 2018 and December 31, 2017 : Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Active Markets Other Significant for Identical Observable Unobservable Balance as of Assets Inputs Inputs September 30, In millions (Level 1) (Level 2) (Level 3) 2018 Assets: Fixed-maturity investments: U.S. Treasury and government agency $ 765 $ 89 $ - $ 854 State and municipal bonds - 757 - 757 Foreign governments - 11 - 11 Corporate obligations 20 1,603 - 1,623 Mortgage-backed securities: Residential mortgage-backed agency - 220 - 220 Residential mortgage-backed non-agency - 30 - 30 Commercial mortgage-backed - 50 7 (1) 57 Asset-backed securities: Collateralized debt obligations - 146 - 146 Other asset-backed - 217 4 (1) 221 Total fixed-maturity investments 785 3,123 11 3,919 Money market securities 147 - - 147 Perpetual debt and equity securities 26 38 - 64 Fixed-income fund - - - 75 (2) Cash and cash equivalents 167 - - 167 Derivative assets: Non-insured derivative assets: Interest rate derivatives - 2 - 2 Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Active Markets Other Significant for Identical Observable Unobservable Balance as of Assets Inputs Inputs September 30, In millions (Level 1) (Level 2) (Level 3) 2018 Assets of consolidated VIEs: Corporate obligations - 9 5 (1) 14 Mortgage-backed securities: Residential mortgage-backed non-agency - 98 - 98 Commercial mortgage-backed - 35 - 35 Asset-backed securities: Collateralized debt obligations - 6 1 (1) 7 Other asset-backed - 9 - 9 Cash 12 - - 12 Loans receivable at fair value: Residential loans receivable - - 428 428 Loan repurchase commitments - - 415 415 Other assets: Currency derivatives - - 14 (1) 14 Other - - 15 (1) 15 Total assets $ 1,137 $ 3,320 $ 889 $ 5,421 Liabilities: Medium-term notes $ - $ - $ 123 (1) $ 123 Derivative liabilities: Insured derivatives: Credit derivatives - 2 27 29 Non-insured derivatives: Interest rate derivatives - 137 - 137 Other - - 7 7 Other liabilities: Other payable - - 5 (1) 5 Liabilities of consolidated VIEs: Variable interest entity notes - 327 382 709 Total liabilities $ - $ 466 $ 544 $ 1,010 ____________ (1) - Unobservable inputs are either not developed by the Company or do not significantly impact the overall fair values of the aggregate financial assets and liabilities. (2) - Investment that was measured at fair value by applying the net asset value per share practical expedient, and was required not to be classified in the fair value hierarchy. Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Active Markets Other Significant for Identical Observable Unobservable Balance as of Assets Inputs Inputs December 31, In millions (Level 1) (Level 2) (Level 3) 2017 Assets: Fixed-maturity investments: U.S. Treasury and government agency $ 1,256 $ 96 $ - $ 1,352 State and municipal bonds - 858 - 858 Foreign governments - 10 - 10 Corporate obligations - 1,338 2 (1) 1,340 Mortgage-backed securities: Residential mortgage-backed agency - 368 - 368 Residential mortgage-backed non-agency - 32 - 32 Commercial mortgage-backed - 60 7 (1) 67 Asset-backed securities: Collateralized debt obligations - 118 - 118 Other asset-backed - 178 5 (1) 183 Total fixed-maturity investments 1,256 3,058 14 4,328 Money market securities 180 - - 180 Perpetual debt and equity securities 26 37 - 63 Fixed-income fund - - - 82 (2) Cash and cash equivalents 122 - - 122 Derivative assets: Non-insured derivative assets: Interest rate derivatives - 2 - 2 Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Active Markets Other Significant for Identical Observable Unobservable Balance as of Assets Inputs Inputs December 31, In millions (Level 1) (Level 2) (Level 3) 2017 Assets of consolidated VIEs: Corporate obligations - 19 - 19 Mortgage-backed securities: Residential mortgage-backed non-agency - 108 - 108 Commercial mortgage-backed - 30 6 (1) 36 Asset-backed securities: Collateralized debt obligations - 8 1 (1) 9 Other asset-backed - 10 - 10 Cash 24 - - 24 Loans receivable at fair value: Residential loans receivable - - 759 759 Corporate loans receivable - - 920 920 Loan repurchase commitments - - 407 407 Other assets: Currency derivatives - - 19 (1) 19 Other - - 14 (1) 14 Total assets $ 1,608 $ 3,272 $ 2,140 $ 7,102 Liabilities: Medium-term notes $ - $ - $ 115 (1) $ 115 Derivative liabilities: Insured derivatives: Credit derivatives - 2 63 65 Non-insured derivatives: Interest rate derivatives - 193 - 193 Other - - 4 4 Other liabilities: Warrants - 6 - 6 Other payable - - 7 (1) 7 Liabilities of consolidated VIEs: Variable interest entity notes - 663 406 1,069 Total liabilities $ - $ 864 $ 595 $ 1,459 ____________ (1) - Unobservable inputs are either not developed by the Company or do not significantly impact the overall fair values of the aggregate financial assets and liabilities. (2) - Investment that was measured at fair value by applying the net asset value per share practical expedient, and was required not to be classified in the fair value hierarchy. Level 3 assets at fair value as of September 30, 2018 and December 31, 2017 represented approximately 16 % and 30 %, respectively, of total assets measured at fair value. Level 3 liabilities at fair value as of September 30, 2018 and December 31, 2017 represented approximately 54 % and 41 %, respectively, of total liabilities measured at fair value. The following tables present the fair values and carrying valu es of the Company’s assets and liabilities that are disclosed at fair value but not reported at fair value on the Company’s consolidated balance sheets as of September 30, 2018 and December 31, 2017 : Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Significant Fair Value Carry Value Active Markets for Other Observable Unobservable Balance as of Balance as of Identical Assets Inputs Inputs September 30, September 30, In millions (Level 1) (Level 2) (Level 3) 2018 2018 Assets: Other investments $ - $ 1 $ - $ 1 $ 1 Assets of consolidated VIEs: Investments held-to-maturity - - 901 901 890 Total assets $ - $ 1 $ 901 $ 902 $ 891 Liabilities: Long-term debt $ - $ 1,132 $ - $ 1,132 $ 2,218 Medium-term notes - - 416 416 615 Investment agreements - - 381 381 314 Liabilities of consolidated VIEs: Variable interest entity notes - 382 900 1,282 1,251 Total liabilities $ - $ 1,514 $ 1,697 $ 3,211 $ 4,398 Financial Guarantees: Gross $ - $ - $ 1,231 $ 1,231 $ 100 Ceded - - 68 68 38 Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Significant Fair Value Carry Value Active Markets for Other Observable Unobservable Balance as of Balance as of Identical Assets Inputs Inputs December 31, December 31, In millions (Level 1) (Level 2) (Level 3) 2017 2017 Assets: Other investments $ - $ 2 $ - $ 2 $ 2 Assets of consolidated VIEs: Investments held-to-maturity - - 916 916 890 Total assets $ - $ 2 $ 916 $ 918 $ 892 Liabilities: Long-term debt $ - $ 1,002 $ - $ 1,002 $ 2,121 Medium-term notes - - 406 406 650 Investment agreements - - 433 433 337 Liabilities of consolidated VIEs: Variable interest entity notes - 352 916 1,268 1,220 Total liabilities $ - $ 1,354 $ 1,755 $ 3,109 $ 4,328 Financial Guarantees: Gross $ - $ - $ 1,785 $ 1,785 $ 1,220 Ceded - - 61 61 39 T h e f ol l owin g t able s p r e s en t i n f o rm a t io n abou t c h ange s i n Le v e l 3 a s s e t s ( i n c ludi n g s h o r t - t e r m in v e s t m e n t s) a n d l iab i li t ie s m e a s u r e d a t f a i r v alu e o n a r e c u rr in g ba s i s f o r t h e three months ended September 30, 2018 a n d 2017 : Changes in Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis for the Three Months Ended September 30, 2018 Change in Unrealized Gains (Losses) for the Period Included in Unrealized Earnings Gains / Unrealized Foreign for Assets (Losses) Gains / Exchange still held Balance, Realized Included (Losses) Recognized Transfers Transfers as of Beginning Gains / in Included in OCI or into out of Ending September 30, In millions of Period (Losses) Earnings in OCI Earnings Purchases Issuances Settlements Sales Level 3 (1) Level 3 (1) Balance 2018 Assets: Commercial mortgage-backed $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 7 $ - $ 7 $ - Other asset-backed 6 - - - - - - - - - (2) 4 - Assets of consolidated VIEs: Corporate obligations 5 - - - - - - - - - - 5 - Collateralized debt obligations 1 - - - - - - - - - - 1 - Loans receivable- residential 683 - 20 - - - - (24) (251) - - 428 21 Loan repurchase commitments 415 - - - - - - - - - - 415 - Currency derivatives 14 - 2 - (2) - - - - - - 14 - Other 14 - 1 - - - - - - - - 15 1 Total assets $ 1,138 $ - $ 23 $ - $ (2) $ - $ - $ (24) $ (251) $ 7 $ (2) $ 889 $ 22 Change in Unrealized (Gains) Losses for the Period Included in Unrealized Unrealized Earnings for (Gains) / (Gains) / Foreign Liabilities Losses Losses Exchange still held Balance, Realized Included Included in Recognized Transfers Transfers as of Beginning (Gains) / in Credit Risk in OCI or into out of Ending September 30, In millions of Period Losses Earnings in OCI Earnings Purchases Issuances Settlements Sales Level 3 (1) Level 3 (1) Balance 2018 Liabilities: Medium-term notes $ 149 $ (5) $ (1) $ 11 $ (1) $ - $ - $ (30) $ - $ - $ - $ 123 $ (2) Credit derivatives 31 6 (4) - - - - (6) - - - 27 (4) Other derivatives 4 - 3 - - - - - - - - 7 3 Other payable 5 - - - - - - - - - - 5 - Liabilities of consolidated VIEs: VIE notes 389 10 3 (11) 5 - 1 (15) - - - 382 8 Total liabilities $ 578 $ 11 $ 1 $ - $ 4 $ - $ 1 $ (51) $ - $ - $ - $ 544 $ 5 _______________ (1) - Transferred in and out at the end of the period. Changes in Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis for the Three Months Ended September 30, 2017 Change in Unrealized Gains (Losses) for the Period Included in Unrealized Earnings for Gains / Unrealized Foreign Assets (Losses) Gains / Exchange still held Balance, Realized Included (Losses) Recognized Transfers Transfers as of Beginning Gains / in Included in OCI or into out of Ending September 30, In millions of Period (Losses) Earnings in OCI Earnings Purchases Issuances Settlements Sales Level 3 (1) Level 3 (1) Balance 2017 Assets: Commercial mortgage-backed $ 7 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ (7) $ - $ - Other asset-backed 5 - - - - - - - - - - 5 - Assets of consolidated VIEs: Commercial mortgage-backed 3 - - - - - - - (3) - - - - Collateralized debt obligations 1 - - - - - - - - - - 1 - Loans receivable- residential 815 - 2 - - - - (58) - - - 759 2 Loans receivable- corporate 875 - 4 - - - - (6) - - - 873 4 Loan repurchase commitments 407 - (1) - - - - - - - - 406 (1) Currency derivatives 9 - 3 - 1 - - - - - - 13 4 Other - - - - - 17 - - - - - 17 - Total assets $ 2,122 $ - $ 8 $ - $ 1 $ 17 $ - $ (64) $ (3) $ - $ (7) $ 2,074 $ 9 Change in Unrealized (Gains) Losses for the Period Included in Unrealized Earnings for (Gains) / Unrealized Foreign Liabilities Losses (Gains) / Exchange still held Balance, Realized Included Losses Recognized Transfers Transfers as of Beginning (Gains) / in Included in OCI or into out of E

Investments

Investments	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Investments	Note 7: Investments Investments, excluding those elected under the fair value option, include debt and equity securities classified as either AFS or held-to-maturity ( “ HTM ”) . T h e f o l l o w i n g t a b l e s p r e s en t t h e a m o r t i z e d c o st , f a i r v a l u e , corresponding gross unrealized gains and losses and OTTI for AFS and HTM investments in the Company’s c o n s o l i d a te d i n v es t m en t p o r tf o l i o a s o f September 30, 2018 a nd December 31, 2017 : September 30, 2018 Gross Gross Other-Than- Amortized Unrealized Unrealized Fair Temporary In millions Cost Gains Losses Value Impairments (1) AFS Investments Fixed-maturity investments: U.S. Treasury and government agency $ 843 $ 20 $ (19) $ 844 $ - State and municipal bonds 659 111 (14) 756 47 Foreign governments 10 - - 10 - Corporate obligations 1,672 6 (122) 1,556 (68) Mortgage-backed securities: Residential mortgage-backed agency 222 - (7) 215 - Residential mortgage-backed non-agency 32 1 (3) 30 - Commercial mortgage-backed 57 - (2) 55 - Asset-backed securities: Collateralized debt obligations 143 - - 143 - Other asset-backed 214 1 (1) 214 1 Total AFS investments $ 3,852 $ 139 $ (168) $ 3,823 $ (20) HTM Investments Assets of consolidated VIEs: Corporate obligations $ 890 $ 13 $ (2) $ 901 $ - Total HTM investments $ 890 $ 13 $ (2) $ 901 $ - _______________ (1) - Represents unrealized gains or losses on OTTI securities recognized in AOCI, which includes the non-credit component of impairments, as well as all subsequent changes in fair value of such impaired securities reported in AOCI. December 31, 2017 Gross Gross Other-Than- Amortized Unrealized Unrealized Fair Temporary In millions Cost Gains Losses Value Impairments (1) AFS Investments Fixed-maturity investments: U.S. Treasury and government agency $ 1,317 $ 34 $ (6) $ 1,345 $ - State and municipal bonds 840 29 (12) 857 - Foreign governments 10 - - 10 - Corporate obligations 1,332 25 (80) 1,277 (72) Mortgage-backed securities: Residential mortgage-backed agency 365 1 (4) 362 - Residential mortgage-backed non-agency 35 1 (4) 32 - Commercial mortgage-backed 66 - - 66 - Asset-backed securities: Collateralized debt obligations 116 - - 116 - Other asset-backed 175 - - 175 1 Total fixed-maturity investments 4,256 90 (106) 4,240 (71) Money market securities 179 - - 179 - Perpetual debt and equity securities 3 1 - 4 - Total AFS investments $ 4,438 $ 91 $ (106) $ 4,423 $ (71) HTM Investments Assets of consolidated VIEs: Corporate obligations $ 890 $ 26 $ - $ 916 $ - Total HTM investments $ 890 $ 26 $ - $ 916 $ - _______________ (1) - Represents unrealized gains or losses on OTTI securities recognized in AOCI, which includes the non-credit component of impairments, as well as all subsequent changes in fair value of such impaired securities reported in AOCI. T h e f ol l owin g t abl e p r e s en t s t h e di s t r i bu t io n b y c on t r a c t u a l m a t u r i t y o f AFS and HTM f i x ed -m a t u r i t y securities at a m o r t i z e d c o st a n d f ai r v alu e a s o f September 30, 2018 . Con t r a c t ua l m a t u r i t y m a y d i f f e r f r o m e x pe c t e d m a t u r i t y a s bo rr ow e r s m a y h a v e t h e r igh t t o c a l l o r p r e p a y ob l iga t ion s. AFS Securities HTM Securities Consolidated VIEs Amortized Amortized In millions Cost Fair Value Cost Fair Value Due in one year or less $ 790 $ 802 $ - $ - Due after one year through five years 677 702 - - Due after five years through ten years 670 589 - - Due after ten years 1,047 1,073 890 901 Mortgage-backed and asset-backed 668 657 - - Total fixed-maturity investments $ 3,852 $ 3,823 $ 890 $ 901 Deposited and Pledged Securities T h e f ai r v alu e o f s e c u r i t ie s o n depo s i t wi t h v a r io u s r egu l a t o r y au t ho r i t ie s a s o f September 30, 2018 and December 31, 2017 wa s $ 10 million . T h e se d epo s i t s a re r equi r e d t o c o m p l y wi t h s t a t e in s u r an ce law s. Pursuant to the Company’s tax sharing agreement, securities held by MBIA Inc. in the Tax Escrow Account are included as “Investments pledged as collateral, at fair value” on the Company’s consolidated balance sheets. I n v e s t m en t ag r ee m en t obligations r equ i re t h e Co m pan y t o ple d g e s e c u r i t i e s a s c o lla t e r al. Securities pledged in connection with investment agreement s may not be repled ged by the investment agreement counterparty. As o f September 30, 2018 a nd December 31, 2017 , t h e f ai r v a l u e o f s e c u r i t ie s p ledge d a s c olla t e r a l for these in v e s t m en t ag r e e m e n t s app r o x i m a t e d $ 320 m i llio n an d $ 353 m i l lion , r e s p e c t i v e l y . T h e Co m pan y ’ s c olla t e r a l a s o f September 30, 2018 c on s i s t e d p r i n c ipal l y o f U . S . T r ea s u ry a n d go v e r n m en t ag e n cy and state and municipal bonds , and wa s p r i m a r il y hel d wi t h m a j o r U . S. ban ks. Impaired Investments The following tables present the gross unrealized losses related to AFS and HTM investments as of September 30, 2018 and December 31, 2017 : September 30, 2018 Less than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized In millions Value Losses Value Losses Value Losses AFS Investments Fixed-maturity investments: U.S. Treasury and government agency $ 396 $ (7) $ 206 $ (12) $ 602 $ (19) State and municipal bonds 92 (3) 123 (11) 215 (14) Foreign governments 9 - - - 9 - Corporate obligations 1,116 (38) 213 (84) 1,329 (122) Mortgage-backed securities: Residential mortgage-backed agency 119 (2) 95 (5) 214 (7) Residential mortgage-backed non-agency - - 14 (3) 14 (3) Commercial mortgage-backed 29 - 19 (2) 48 (2) Asset-backed securities: Collateralized debt obligations 73 - - - 73 - Other asset-backed 121 (1) 30 - 151 (1) Total AFS investments $ 1,955 $ (51) $ 700 $ (117) $ 2,655 $ (168) HTM Investments Assets of consolidated VIEs: Corporate obligations $ 313 $ (2) $ - $ - $ 313 $ (2) Total HTM investments $ 313 $ (2) $ - $ - $ 313 $ (2) December 31, 2017 Less than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized In millions Value Losses Value Losses Value Losses AFS Investments Fixed-maturity investments: U.S. Treasury and government agency $ 353 $ (1) $ 124 $ (5) $ 477 $ (6) State and municipal bonds 203 (8) 116 (4) 319 (12) Foreign governments 8 - - - 8 - Corporate obligations 425 (3) 163 (77) 588 (80) Mortgage-backed securities: Residential mortgage-backed agency 105 (1) 156 (3) 261 (4) Residential mortgage-backed non-agency - - 14 (4) 14 (4) Commercial mortgage-backed 27 - 5 - 32 - Asset-backed securities: Collateralized debt obligations 12 - - - 12 - Other asset-backed 71 - 39 - 110 - Total AFS investments $ 1,204 $ (13) $ 617 $ (93) $ 1,821 $ (106) Gross unrealized losses on AFS investments increased as of September 30, 2018 compared with December 31, 2017 primarily due to higher interest rates . With the weighting applied on the fair value of each security relative to the total fair value, the weighted average contractual maturity of securities in an unrealized loss position as of September 30, 2018 and December 31, 2017 was 13 and 12 years , respectively . As of September 30, 2018 and December 31, 2017 , there were 131 and 133 securities, respectively, that were in an unrealized loss position for a conti nuous twelve-month period or longer, of which , fair value s of 75 and 24 securities, respectively, were below book value by more than 5 %. The following table presents the distribution of securities in an unrealized loss position for a continuous twelve-month period or longer where fair value was below book value by more tha n 5% as of September 30, 2018 : AFS Securities Percentage of Fair Value Number of Book Value Fair Value Below Book Value Securities (in millions) (in millions) > 5% to 15% 60 $ 368 $ 338 > 15% to 25% 11 61 50 > 25% to 50% - - - > 50% 4 100 32 Total 75 $ 529 $ 420 The Company concluded that it does not have the intent to sell securities in an unrealized loss position and it is more likely than not, that it w ould not have to sell these securities before recovery of their cost basis. In making this conclusion, the Company examined the cash flow projections for its investment portfolios, the potential sources and uses of cash in its businesses , and the cash resources available to its business other than sales of securities. It also considered the existence of any risk management or other plans as of September 30, 2018 that would require the sale of impaired securities. Impaired securities tha t the Company intends to sell before the expected recovery of such securities’ fair values have been written down to fair value. Other-Than-Temporary Impairments The Company’s fixed - maturity securities for which fair value is less than amortized cost are reviewed quarterly in order to determin e whether a credit loss exists. The portion of certain OTTI losses on fixed - maturity securities that does not represent credit losses is recognized in AOCI. Refer to “Note 8: Investments” in the Notes to Con solidated Financial Statements included in the Company’s Annual Report on Form 10 - K for the year ended December 31, 2017 for a disc ussion of the Company’s policy for OTTI and its determination of credit loss. The following table presents the amount of credi t loss impairments recognized in earnings on fixed - maturity securities held by MBIA as of the dates indica ted, for which a portion of the OTTI losses was recognized in AOCI, and the corresponding changes in such amounts . The additional credit loss impairments for the three and nine months ended September 30, 2018 were primarily related to an impaired security for which a loss was rec ognized as the difference between the amortized cost and net present value of projected cash flows. This OTTI resulted from liquidity concerns and other adverse financial conditions of the issuer. The additional credit loss impairment for the nine months ended September 30, 2017 was primarily related to municipal bonds for which a loss was recognized as the difference between their amortized cost and their recovery value in the second quarter of 2017 . This OTTI resulted from liquidity concerns, recent credi t rating downgrades and other adverse financial conditions of the issuer. The reduction from credit loss impairment for the three and nine months ended September 30, 2017 was primarily related to municipal bonds previously impaired which were further impai red to fair value during the third quarter 2017 . In millions Three Months Ended September 30, Nine Months Ended September 30, Credit Losses Recognized in Earnings Related to Other-Than-Temporary Impairments 2018 2017 2018 2017 Beginning balance $ 34 $ 42 $ 32 $ 29 Additions for credit loss impairments recognized in the current period on securities not previously impaired - - - 11 Additions for credit loss impairments recognized in the current period on securities previously impaired 1 2 3 4 Reductions for credit loss impairments previously recognized on securities sold during the period - (2) - (2) Reductions for credit loss impairments previously recognized on securities impaired to fair value during the period - (11) - (11) Ending balance $ 35 $ 31 $ 35 $ 31 The Company does not recognize OTTI on securities insured by MBIA Corp. and National since those securities, whether or not owned by the Company, are evaluated for impairments in accordance with its loss reserving policy. The following table provides information about securities held by the Company as of September 30, 2018 that were in an unrealized loss position and insured by a financial guarantor, along with the amount of insurance loss reserves corresponding to the pa r amount owned by the Company: Unrealized Insurance Loss In millions Fair Value Loss Reserve (2) Mortgage-backed: MBIA (1) $ 14 $ (3) $ 14 Corporate obligations: MBIA (1) 70 (12) - Other: MBIA (1) 6 - - Other 2 - - Total other 8 - - Total $ 92 $ (15) $ 14 _______________ (1) - Includes investments insured by MBIA Corp. and National. (2) - Insurance loss reserve estimates are based on the proportion of par value owned to the total amount of par value insured. Sales of Available-for-Sale Investments Gross r eali z e d ga i n s and l o s s e s are recorded within “Net gains (losses) on financial instruments at fair value and foreign exchange” on the Company’s consolidated statements of operations . The proceeds and the gross realized gains and losses from sales of fixed-maturity securities held as AFS for the three and nine months ended September 30, 2018 and 2017 are as follows: Three Months Ended September 30, Nine Months Ended September 30, In millions 2018 2017 2018 2017 Proceeds from sales $ 583 $ 312 $ 1,647 $ 1,300 Gross realized gains $ 1 $ 5 $ 4 $ 24 Gross realized losses $ (2) $ (5) $ (15) $ (9) Equity Investments Unrealized gains and losses recognized on equity investments held as of September 30, 2018 for the three and nine months ended September 30, 2018 are as follo ws: In millions Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 Net gains (losses) recognized during the period on equity securities $ 3 $ 3 Less: Net gains (losses) recognized during the period on equity securities sold during the period - 1 Unrealized gains (losses) recognized during the period on equity securities still held as of September 30, 2018 $ 3 $ 2

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Derivative Instruments	Note 8: Derivative Instruments U.S. Public Finance Insurance The Company’s derivative exposure within its U.S. public finance insurance operations primarily consists of insured interest rate and inflation-linked swaps related to insured U.S. public finance debt issues. These derivatives do not qualify for the financial guarantee scope exception and are accounted for as derivative instruments . Corporate The Company has entered into derivative instrument s primarily consisting of interest rate swaps to manage the risks a ssociated with fluctuations in interest rates affecting the value of certain assets and liabilities . I n t e r na t i on a l and S t r u c t u r e d F i n an c e I n s u r an c e The Company has entered into a derivative instrument to provide financial guarantee insurance to a structured finance transaction that do es not qualify for the financial guarantee scope exception and, therefore, is accounted for as a derivative. The insured CDS contract, referencing CMBS, is intended to be held for the entire term of the contract unles s a settlement with the counterparty is negotiated . The Company no longer insures new CDS contracts except for transactions related to the restructuring or reduction of existing derivative exposure. The Company’s derivative exposure within its international and structured finance insurance segment also includes insured interest rate and inflation-linked swaps related to insured debt issues. The Company has also entered into a derivative contract as a result of a commutation that occurr ed in 2014. Changes in the fair value of the Company’s non-insured derivative are included in “Net gains (losses) on financial instruments at fair value and foreign exchange” on the Company’s consolidated statements of operations. Variable Interest Entities A V IE consolidated by the Company ha s entered into a cross currency swap, which was entered into to manage the variability in cash flows resulting from fluctuations in foreign currency rates . Credit Derivatives Sold The following table s present information about credit derivatives sold by the Company’s insurance operations that were outstanding as of September 30, 2018 and December 31, 2017 . Credit ratings represent the lower of underlying ratings assigned to the collateral by Moody ’s , S&P or MBIA. $ in millions As of September 30, 2018 Notional Value Credit Derivatives Sold Weighted Average Remaining Expected Maturity AAA AA A BBB Below Investment Grade Total Notional Fair Value Asset (Liability) Insured credit default swaps 0.3 Years $ - $ - $ - $ - $ 77 $ 77 $ (27) Insured swaps 15.5 Years - 107 1,539 915 - 2,561 (2) Total notional $ - $ 107 $ 1,539 $ 915 $ 77 $ 2,638 Total fair value $ - $ - $ (1) $ (1) $ (27) $ (29) $ in millions As of December 31, 2017 Notional Value Credit Derivatives Sold Weighted Average Remaining Expected Maturity AAA AA A BBB Below Investment Grade Total Notional Fair Value Asset (Liability) Insured credit default swaps 1.0 Years $ - $ - $ - $ - $ 127 $ 127 $ (63) Insured swaps 15.5 Years - 117 1,818 846 20 2,801 (2) Total notional $ - $ 117 $ 1,818 $ 846 $ 147 $ 2,928 Total fair value $ - $ - $ (1) $ (1) $ (63) $ (65) Internal credit ratings assigned by MBIA on the underlying collateral are derived b y t h e Co m pan y ’ s s u r v e ill a n ce g r ou p . I n a ss ign i n g a n i n t e r n a l r a t i n g , c u rr en t s t a t u s r epo r t s f r o m i ss ue rs an d t r u s t ee s, a s w el l a s p ubli c l y a v ai l able t r a n s a c t i o n - s p e c i f i c i n f o rm a t ion , a re r e v iew e d . A l s o , whe re ap p r o p r ia t e , c a sh f l o w a n al ys e s an d c ol l a t e r a l v a l ua t ion s a re c on s id e r e d . T h e m a x i m u m po t en t ia l a m ou n t o f f u t u re pa ym en t s ( un d i s c o un t ed ) o n insured CDS and i n s u r e d s w a p s is e s t i m a t e d a s t he no t ion a l v a l u e o f s u ch c o n t r a c t s. M B I A m a y hol d r e c ou rse p r o v i s ion s wi t h t hi rd pa r t ie s i n de r i v a t i ve instrument s t h r o u g h s ub r o ga t i on r igh t s , wh e r e b y i f M B I A m a k e s a c lai m pa ym en t , i t may be en t i t l e d t o an y r i gh t s o f t h e in s u r ed c oun t e r pa r t y, in c lu d in g t h e r ig h t t o an y a ss e t s hel d a s c o lla t e r al. Counterparty Credit Risk The Company manages counterparty credit risk on an individual counterparty basis through master netting agreements covering derivative instruments in the corporate segment. These agreements allow the Company to contractually net amounts due from a counterparty with those amounts due to such counterparty when certain triggering events occur. The Company only executes swaps under master netting agreements, which typically contain mutual credit downgrade provisions that generally provide the ability to require assignment or termination in the event either MBIA or the counterparty is downgraded below a specified credit rating. Under these agreements, the Company may receive or provide cash, U.S. Treasury or other highly rated securities to secure counterparties’ exposure to the Company or its exposure to counterparties, respectively. Such collateral is available to the holder to pay for replacing the counterparty in the event that the counterparty defaults. As of September 30, 2018 and December 31, 2017 , the Company did not hold or post cash collateral to derivative counterparties . As of September 30, 2018 and December 31, 2017 , the Company had securities with a fair value of $ 183 mi llion and $ 237 million , respectively, posted to derivative counterparties and th ese amount s are included within “Fixed-maturity securities held as available-for-sale, at fair value” on the Company’s consolidated balance sheets. As of September 30, 2018 and December 31, 2017 , the fair value on one Credit Support Annex (“CSA”) was $ 2 million . This CSA governs collateral posting requirements between MBIA and its derivative counterparties . The Company did not receive collateral due t o the Company’s credit rating, which was below the CSA minimum credit ratings level for holding counterparty collateral . As of September 30, 2018 and December 31, 2017 , the counterpart y was rated A1 by Moody’s and A by S& P. Financial Statement Presentation The fair value of amounts recognized for eligible derivative contracts executed with the same counterparty under a master netting agreement, including any cash collateral that may have been received or posted by the Company, is presented on a net basis in accordance with accounting guidance for the offsetting of fair value amounts related to derivative instruments. Insured CDS and insured swaps are not subject to master netting agreements. VIE derivative assets and liabilities are not presented net of any m aster netting agreements. Counterparty netting of derivative assets and liabilities offsets balances in “Interest rate swaps” , when applicable. The following table presents the total fair value of the Company’s derivative assets and liabilities by instrume nt and balance sheet location, before counterparty netting and posting of cash collateral, as of September 30, 2018 : In millions Derivative Assets (1) Derivative Liabilities (1) Notional Amount Fair Fair Derivative Instruments Outstanding Balance Sheet Location Value Balance Sheet Location Value Not designated as hedging instruments: Insured credit default swaps $ 77 Other assets $ - Derivative liabilities $ (27) Insured swaps 2,561 Other assets - Derivative liabilities (2) Interest rate swaps 722 Other assets 2 Derivative liabilities (136) Interest rate swaps-embedded 296 Medium-term notes - Medium-term notes (10) Currency swaps-VIE 64 Other assets-VIE 14 Derivative liabilities-VIE - All other 49 Other assets - Derivative liabilities (8) Total non-designated derivatives $ 3,769 $ 16 $ (183) __________ (1) - In accordance with the accounting guidance for derivative instruments and hedging activities, the balance sheet location of the Company’s embedded derivative instruments is determined by the location of the related host contract. The following table presents the total fair value of the Company’s derivat ive assets and liabilities by instrument and balance sheet location, before counterparty netting and posting of cash collateral , as of December 31, 2017 : In millions Derivative Assets (1) Derivative Liabilities (1) Notional Amount Fair Fair Derivative Instruments Outstanding Balance Sheet Location Value Balance Sheet Location Value Not designated as hedging instruments: Insured credit default swaps $ 127 Other assets $ - Derivative liabilities $ (63) Insured swaps 2,801 Other assets - Derivative liabilities (2) Interest rate swaps 747 Other assets 2 Derivative liabilities (193) Interest rate swaps-embedded 305 Medium-term notes 1 Medium-term notes (6) Currency swaps-VIE 69 Other assets-VIE 19 Derivative liabilities-VIE - All other 49 Other assets - Derivative liabilities (4) All other-embedded 2 Other investments - Other investments (1) Total non-designated derivatives $ 4,100 $ 22 $ (269) __________ (1) - In accordance with the accounting guidance for derivative instruments and hedging activities, the balance sheet location of the Company’s embedded derivative instruments is determined by the location of the related host contract. T h e f ol l owin g t able p r e s en t s t h e e f f e ct o f d e r i v a t i ve i n s t r u m en t s o n t h e c o n s olida t e d s t a t e m en t s o f ope r a t ion s f o r t h e three months ended September 30, 2018 and 2017 : In millions Derivatives Not Designated as Three Months Ended September 30, Hedging Instruments Location of Gain (Loss) Recognized in Income on Derivative 2018 2017 Insured credit default swaps Unrealized gains (losses) on insured derivatives $ 4 $ 6 Insured credit default swaps Realized gains (losses) and other settlements on insured derivatives (5) (7) Interest rate swaps Net gains (losses) on financial instruments at fair value and foreign exchange 7 (3) Currency swaps-VIE Net gains (losses) on financial instruments at fair value and foreign exchange-VIE - 4 All other Net gains (losses) on financial instruments at fair value and foreign exchange (4) - Total $ 2 $ - T h e f ol l owin g t able p r e s en t s t h e e f f e ct o f d e r i v a t i ve i n s t r u m en t s o n t h e c o n s olida t e d s t a t e m en t s o f ope r a t ion s f o r t h e nine months ended September 30, 2018 and 2017 : In millions Derivatives Not Designated as Nine Months Ended September 30, Hedging Instruments Location of Gain (Loss) Recognized in Income on Derivative 2018 2017 Insured credit default swaps Unrealized gains (losses) on insured derivatives $ 36 $ (10) Insured credit default swaps Realized gains (losses) and other settlements on insured derivatives (49) (41) Interest rate swaps Net gains (losses) on financial instruments at fair value and foreign exchange 33 (8) Currency swaps-VIE Net gains (losses) on financial instruments at fair value and foreign exchange-VIE (5) (6) All other Net gains (losses) on financial instruments at fair value and foreign exchange (4) (19) Total $ 11 $ (84)

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
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Income Taxes	Note 9: Income Taxes The Company’s i n c o m e t a x e s a nd t he r e l a t e d e f f e c ti v e t a x r a t e s f o r t he three and nine months ended September 30, 2018 a nd 2017 a re a s fo l l o ws : Three Months Ended September 30, Nine Months Ended September 30, In millions 2018 2017 2018 2017 Income (loss) before income taxes $ (45) $ (273) $ (287) $ (603) Provision (benefit) for income taxes $ - $ (6) $ 2 $ 965 Effective tax rate -% 2.2% -0.7% -160.0% F or the nine months ended September 30, 2018 and 2017 , the Company’s effective tax rate applied to its loss before income taxes was less than the U.S. statutory tax rate primarily due to a full valuation allowance against its net deferred tax asset. Deferred Tax Asset, Net of Valuation Allowance On June 26, 2017, S&P downgraded the financial strength rating of National , which led the Company to cease its efforts to actively pursue writing new financial guarantee business. In addition to National’s cessation of new business activity, there was an increase in loss and LAE due to changes in assumptions on certain Puerto Rico credits. As a result of the increase in loss and LAE, the Company has a three-year cumulative loss , which is considered significant negative evidence in the assessment of its abi lity to use its deferred tax assets. In addition, the Company considered all available positive and negative evidence as required by GAAP, to estimate if sufficient taxable income will be generated to use its deferred tax assets. After considering all posi tive and negative evidence, including the Company’s inability to objectively identify and forecast future sources of taxable income, the Company c oncluded in the second quarter of 2017 it did not have sufficient positive evidence to support its ability to use its deferred tax assets before they would expire. Accordingly, the Company has a full valuation allowance against its net deferred tax asset of $841 million and $770 million as of September 30, 2018 and December 31, 2017, respectively. The Company will con tinue to analyze the valuation allowance on a quarterly basis. On December 22, 2017, the President of the United States signed into law the Tax Cuts and Jobs Act (the “Act”) , which among other items reduces the federal corporate tax rate to 21 % effective J anuary 1, 2018. As a result, during the fourth quarter of 2017, the Company revalued its net tax deferred tax asset using the newly enacted tax rate of 21% . The Company’s revaluation of its net deferred tax asset is subject to further clarifications of the new law that cannot be estimated at this time. However, as further clarification of the new law is determined, any adjustment would be offset with a valuation allowance resulting in no change to the Company’s net deferred tax asset. The Company does not a nticipate future cash expenditures as a result of the reduction to its net deferred tax asset. Under the Act, net operating losses (“NOLs”) of property and casualty insurance companies retain their current two-year carryback and 20-year carryforward period s and will not be subject to the 80 percent taxable income limitation and indefinite lived carryforward period applicable to general corporate NOLs. Therefore, NOLs generated after 2017 by the Company’s insurance companies and non-insurance companies will be treated differently under the Act. A cc o u n t i n g f o r U n c e r t a i n t y i n I n c o m e T ax e s The C o m p a ny ’ s po l i c y is t o r eco r d a n d d i s c l o s e an y c h an g e i n unrecognized tax benefits (“ U T B ”) an d r e l a t e d i n t e r es t a n d /or p e n a l t i e s t o i n c o m e t a x i n t h e co n s o l i d a t e d s t a t e m en t s o f o pe r a t i ons . The Company includes interest as a component of income tax expense. As of September 30, 2018 and December 31, 2017 , the Company had no UTB. Federal income tax returns through 2011 have been examined or surveyed. As of September 30, 2018 , the Company’s NOL is approximately $ 2.5 billion . The NOL will expire between tax years 20 31 through 203 7 . As of September 30, 2018 , the Company has a foreign tax credit carryforward of $ 62 million, which will expire between tax years 2019 through 2028. As of September 30, 2018 , the Company has an alternative minimum tax (“AMT”) credit carryforward of $ 24 million, which does not expire. As a result of tax reform, AMT credits are now fully refundable no later than 2022. The AMT credit has been reclassed out of the deferred tax asset and into other assets as the AMT credits are now a receivable. Section 382 of the Internal Revenue Code On May 2, 2018, MB IA Inc.’s shareholders ratified an amendment to the Company’s By-Laws, which had been adopted earlier by MBIA Inc.’s Board of Directors. The amendment places restrictions on certain acquisitions of Company stock that otherwise may have increased the likeli hood of an ownership change within the meaning of Section 382 of the Internal Revenue Code. The amendment generally prohibits a person from becoming a “Section 382 five-percent shareholder” by acquiring, directly or by attribution, 5% or more of the outsta nding shares of the Company’s common stock and will generally restrict existing “Section 382 five-percent shareholders” from increasing their ownership interest under Section 382 by more than one percentage point over their percentage stock ownership immed iately prior to the effective date of the amendment or, if lower, their percentage thereafter.

Business Segments

Business Segments	9 Months Ended
	Sep. 30, 2018
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Business Segments	Note 10: Business Segments As defined by segment reporting, an operating segment is a component of a company (i) that engages in business activities from which it earns revenue and incurs expenses, (ii) whose operating results are regularly reviewed by the Chief Operating Decision Maker to assess the performance of the segment and to make decisions about the allocation of resources to the segment and, (iii) for which discrete financial information is available. The Company manages its businesses across three oper ating segments: 1) U.S. public finance insurance; 2) corporate; and 3) international and structured finance insurance. The Company’s U.S. public finance insurance business is operated through National and its international and structured finance insurance business is operated through MBIA Corp. The following sections provide a description of each of the Company’s reportable operating segments. U.S. Public Finance Insurance The Company’s U.S. public finance insurance portfolio is managed through National. T he financial guarantees issued by National provide unconditional and irrevocable guarantees of the payment of the principal of, and interest or other amounts owing on, U.S. public finance insured obligations when due. The obligations are not subject to acc eleration, except that National may have the right, at its discretion, to accelerate insured obligations upon default or otherwise. National ’s guarantees insure municipal bonds, including tax-exempt and taxable indebtedness of U.S. political subdivisions, as well as utilit ies , airports, health care institutions, higher educational facilities, student loan issuers, housing authorities and other similar agencies and obligations issued by private entities that finance projects that serve a substantial public p urpose. Municipal bonds and privately issued bonds used for the financing of public purpose projects are generally supported by taxes, assessments, fees or tariffs related to the use of these projects, lease payments or other similar types of revenue strea ms. Corporate The Company’s corporate segment consists of general corporate activities, including providing support services to MBIA Inc.’s subsidiaries as well as asset and capital management. Support services are provided by the Company’s service compan y, MBIA Services Corporation, and include , among others, management, legal, accounting, treasury, information technology, and insurance portfolio surveillance, on a fee-for-service basis. Capital management includes activities related to servicing obligati ons issued by MBIA Inc. and its subsidiaries, MBIA Global Funding, LLC (“GFL”) and MBIA Investment Management Corp. (“IMC”) . MBIA Inc. issued debt to finance the operations of the MBIA group. GFL raised funds through the issuance of MTNs with varying matur ities, which were in turn guaranteed by MBIA Corp. GFL lent the proceeds of these MTN issuances to MBIA Inc. IMC, along with MBIA Inc., provided customized investment agreements, guaranteed by MBIA Corp., for bond proceeds and other public funds for such p urposes as construction, loan origination, escrow and debt service or other reserve fund requirements. The Company has ceased issuing new MTNs and investment agreements and the outstanding liability balances and corresponding asset balances have declined o ver time as liabilities matured, terminated or were called or repurchased. All of the debt within the corporate segment is managed collectively and is serviced by available liquidity . International and Structured Finance Insurance The Company’s international and structured finance insurance segment is principally conducted through MBIA Corp. The financial guarantees issued by MBIA Corp. generally provide unconditional and irrevocable guarantees of the payment of principal of, and in terest or other amounts owing on, non-U.S. public finance and global structured finance insured obligations when due, or in the event MBIA Corp. has the right, at its discretion, to accelerate insured obligations upon default or otherwise. MBIA Corp. insur es the investment contracts written by MBIA Inc., and if MBIA Inc. were to have insufficient assets to pay amounts due upon maturity or termination, MBIA Corp. would make such payments. MBIA Corp. insures debt obligations of the following affiliates: MBIA Inc.; GFL; IMC; MZ Funding LLC ; and LaCrosse Financial Products, LLC, a wholly-owned affiliate, to which MBIA Insurance Corp oration has written insurance policies guaranteeing the obligations under CDS . Certain policies cover payments potentially due under CDS, including termination payments that may become due in certain circumstances, including the occurrence of certain insolvency or payment defaults under the CDS or derivatives contracts by the insured counterparty or by the guarantor. MBIA Corp. insure s non -U.S. public finance and global structured finance obligations, including asset-backed obligations. MBIA Corp. has insured sovereign-related and sub-sovereign bonds, utilities , privately issued bon ds used for the financing of projects that include toll roads, bridges, airports, public transportation facilities, and other types of infrastructure projects serving a substantial public purpose. Global structured finance and asset-backed obligations typi cally are securities repayable from expected cash flows generated by a specified pool of assets, such as residential and commercial mortgages, insurance policies, consumer loans, corporate loans and bonds, trade and export receivables, and leases for equip ment, aircraft and real estate property. MBIA Corp. has also written policies guaranteeing obligations under certain other derivative contracts, including termination payments that may become due upon certain insolvency or payment defaults of the financial guarantor or the issuer. The Company is no longer insuring new credit derivative contracts except for transactions related to the restructuring or reduction of existing derivative exposure. MBIA Corp. has not written any meaningful amount of business since 2008. Segments Results The following tables provide the Company’s segment results for the three months ended September 30, 2018 and 2017 : Three Months Ended September 30, 2018 U.S. International Public and Structured Finance Finance In millions Insurance Corporate Insurance Eliminations Consolidated Revenues (1) $ 45 $ 7 $ 58 $ - $ 110 Net change in fair value of insured derivatives - - (1) - (1) Net gains (losses) on financial instruments at fair value and foreign exchange 1 17 (13) - 5 Net investment losses related to other-than-temporary impairments (1) - - - (1) Net gains (losses) on extinguishment of debt - 3 - - 3 Other net realized gains (losses) - - 1 - 1 Revenues of consolidated VIEs - - (12) - (12) Inter-segment revenues (2) 7 11 6 (24) - Total revenues 52 38 39 (24) 105 Losses and loss adjustment 48 - (2) - 46 Operating 5 13 9 - 27 Interest - 20 32 - 52 Expenses of consolidated VIEs - - 25 - 25 Inter-segment expenses (2) 10 5 9 (24) - Total expenses 63 38 73 (24) 150 Income (loss) before income taxes (11) - (34) - (45) Provision (benefit) for income taxes (3) 2 - 1 - Net income (loss) $ (8) $ (2) $ (34) $ (1) $ (45) Identifiable assets $ 4,453 $ 1,062 $ 5,026 $ (2,180) (3) $ 8,361 ________________ (1) - Represents the sum of third-party financial guarantee net premiums earned, net investment income, insurance-related fees and reimbursements and other fees. (2) - Represents intercompany premium income and expense and intercompany interest income and expense pertaining to intercompany receivables and payables. (3) - Consists primarily of intercompany reinsurance balances and repurchase agreements. Three Months Ended September 30, 2017 U.S. International Public and Structured Finance Finance In millions Insurance Corporate Insurance Eliminations Consolidated Revenues (1) $ 70 $ 7 $ 10 $ - $ 87 Net change in fair value of insured derivatives - - (1) - (1) Net gains (losses) on financial instruments at fair value and foreign exchange 2 (15) 2 - (11) Net investment losses related to other-than-temporary impairments (71) - - - (71) Net gains (losses) on extinguishment of debt - 1 - - 1 Other net realized gains (losses) (1) (1) 1 - (1) Revenues of consolidated VIEs - - 29 - 29 Inter-segment revenues (2) 4 15 11 (30) - Total revenues 4 7 52 (30) 33 Losses and loss adjustment 141 - 64 - 205 Operating 8 14 7 - 29 Interest - 22 28 - 50 Expenses of consolidated VIEs - - 22 - 22 Inter-segment expenses (2) 16 - 14 (30) - Total expenses 165 36 135 (30) 306 Income (loss) before income taxes (161) (29) (83) - (273) Provision (benefit) for income taxes (55) (1) 1 49 (6) Net income (loss) $ (106) $ (28) $ (84) $ (49) $ (267) Identifiable assets $ 5,051 $ 1,205 $ 5,320 $ (2,032) (3) $ 9,544 ________________ (1) - Represents the sum of third-party financial guarantee net premiums earned, net investment income, insurance-related fees and reimbursements and other fees. (2) - Represents intercompany premium income and expense and intercompany interest income and expense pertaining to intercompany receivables and payables. (3) - Consists primarily of intercompany reinsurance balances and repurchase agreements. T h e f ol l owin g t able s p r o v id e t h e Company’s segment r e s u l t s f o r t h e nine months ended September 30, 2018 an d 2017 : Nine Months Ended September 30, 2018 U.S. International Public and Structured Finance Finance In millions Insurance Corporate Insurance Eliminations Consolidated Revenues (1) $ 139 $ 20 $ 98 $ - $ 257 Net change in fair value of insured derivatives - - (13) - (13) Net gains (losses) on financial instruments at fair value and foreign exchange (13) 48 (17) - 18 Net investment losses related to other-than-temporary impairments (3) - - - (3) Net gains (losses) on extinguishment of debt - 3 - - 3 Other net realized gains (losses) - (2) 2 - - Revenues of consolidated VIEs - - (72) - (72) Inter-segment revenues (2) 20 36 18 (74) - Total revenues 143 105 16 (74) 190 Losses and loss adjustment 184 - (7) - 177 Operating 14 39 21 - 74 Interest - 60 95 - 155 Expenses of consolidated VIEs - - 71 - 71 Inter-segment expenses (2) 34 14 27 (75) - Total expenses 232 113 207 (75) 477 Income (loss) before income taxes (89) (8) (191) 1 (287) Provision (benefit) for income taxes (20) (31) (5) 58 2 Net income (loss) $ (69) $ 23 $ (186) $ (57) $ (289) Identifiable assets $ 4,453 $ 1,062 $ 5,026 $ (2,180) (3) $ 8,361 ________________ (1) - Represents the sum of third-party financial guarantee net premiums earned, net investment income, insurance-related fees and reimbursements and other fees. (2) - Represents intercompany premium income and expense and intercompany interest income and expense pertaining to intercompany receivables and payables. (3) - Consists primarily of intercompany reinsurance balances and repurchase agreements. Nine Months Ended September 30, 2017 U.S. International Public and Structured Finance Finance In millions Insurance Corporate Insurance Eliminations Consolidated Revenues (1) $ 200 $ 23 $ 54 $ - $ 277 Net change in fair value of insured derivatives - - (51) - (51) Net gains (losses) on financial instruments at fair value and foreign exchange 20 (54) (21) - (55) Net investment losses related to other-than-temporary impairments (84) - - - (84) Net gains (losses) on extinguishment of debt - 9 - - 9 Other net realized gains (losses) (1) (3) 40 - 36 Revenues of consolidated VIEs - - 50 - 50 Inter-segment revenues (2) 14 46 31 (91) - Total revenues 149 21 103 (91) 182 Losses and loss adjustment 310 - 159 - 469 Operating 34 46 25 - 105 Interest - 66 82 - 148 Expenses of consolidated VIEs - - 63 - 63 Inter-segment expenses (2) 47 2 42 (91) - Total expenses 391 114 371 (91) 785 Income (loss) before income taxes (242) (93) (268) - (603) Provision (benefit) for income taxes (86) 1,069 1,143 (1,161) 965 Net income (loss) $ (156) $ (1,162) $ (1,411) $ 1,161 $ (1,568) Identifiable assets $ 5,051 $ 1,205 $ 5,320 $ (2,032) (3) $ 9,544 ________________ (1) - Represents the sum of third-party financial guarantee net premiums earned, net investment income, insurance-related fees and reimbursements and other fees. (2) - Represents intercompany premium income and expense and intercompany interest income and expense pertaining to intercompany receivables and payables. (3) - Consists primarily of intercompany reinsurance balances and repurchase agreements.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2018
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Earnings Per Share	Note 11: Earnings Per Share Earnings per share is calculated using the two-class method in which earnings are allocated to common stock and participating securities based on their rights to receive nonforfeitable dividends or dividend equivalents. The Company grants restricted stock and restricted stock units to certain employees and non-employee directors in accordance with the Company’s long-term incentive programs, which entitle the participants to receive nonf orfeitable dividends or dividend equivalents during the vesting period on the same basis as those dividends are paid to common shareholders. These unvested stock awards represent participating securities. During periods of net income, the calculation of ea rnings per share exclude the income attributable to participating securities in the numerator and the dilutive impact of these securities from the denominator. During periods of net loss, no effect is given to participating securities in the numerator and the denominator excludes the dilutive impact of these securities since they do not share in the losses of the Company. Basic earnings per share excludes dilution and is computed by dividing net income available to common shareholders by the weighted avera ge number of common shares outstanding during the period. D iluted earnings per share reflects the dilutive effect of all stock options , warrants and unvested restricted stock outstanding during the period that could potentially result in the issuance of co mmon stock. The dilution from stock options, warrants and unvested restricted stock are calculated by applying the two-class method and using the treasury stock method. The treasury stock method assumes the proceeds from the exercise of stock options and w arrants or the unrecognized compensation expense from unvested restricted stock will be used to purchase shares of the Company’s common stock at the average market price during the period. If the potentially dilutive securities disclosed in the table below are either exercised or vested, the transaction would be net share settled resulting in a significantly lower impact to the outstanding share balance in comparison to the total amount of the potentially dilutive securities. During periods of net loss, sto ck options, warrants and unvested restricted stock are excluded from the calculation because they would have an antidilutive effect. Therefore, in periods of net loss, the calculation of basic and diluted earnings per share would result in the same value. In the second quarter of 2018, the holder of all of the outstanding MBIA Inc. warrants exercised its right to purchase shares of MBIA Inc. common stock. As of September 30, 2018 , there were no warrants outstanding. Refer to “Note 1: Business Developments and R isks and Uncertainties” for further information about the exercise of the warrants. The following table presents the computation of basic and diluted earnings per share for the three and nine months ended September 30, 2018 and 2017 : Three Months Ended September 30, Nine Months Ended September 30, In millions except per share amounts 2018 2017 2018 2017 Basic earnings per share: Net income (loss) available to common shareholders $ (45) $ (267) $ (289) $ (1,568) Basic weighted average shares (1) 89.5 123.0 89.1 126.6 Net income (loss) per basic common share $ (0.50) $ (2.17) $ (3.24) $ (12.38) Diluted earnings per share: Net income (loss) available to common shareholders $ (45) $ (267) $ (289) $ (1,568) Diluted weighted average shares 89.5 123.0 89.1 126.6 Net income (loss) per diluted common share $ (0.50) $ (2.17) $ (3.24) $ (12.38) Potentially dilutive securities excluded from the calculation of diluted EPS because of antidilutive affect (2) 1.4 14.4 1.4 14.4 _________ (1) - Includes 0.9 million and 0.3 million of participating securities that met the service condition and were eligible to receive nonforfeitable dividends or dividend equivalents for the three months ended September 30, 2018 and 2017, respectively. Includes 0.8 million and 0.3 of participating securities that met the service condition and were eligible to receive nonforfeitable dividends or dividend equivalents for the nine months ended September 30, 2018 and 2017, respectively. (2) - Includes securities that if exercised or vested would be net share settled resulting in a significantly lower impact to the outstanding share balance.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2018
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Accumulated Other Comprehensive Income [Text Block]	Note 12: Accumulated Other Comprehensive Income T h e followin g tabl e present s th e changes in the components of AOCI fo r th e nine months ended September 30, 2018 : Unrealized Instrument-Specific Gains (Losses) Credit Risk of on AFS Foreign Currency Liabilities Measured In millions Securities, Net Translation, Net at Fair Value, Net Total Balance, December 31, 2017 $ (10) $ (9) $ - $ (19) ASU 2016-01 transition adjustment (2) - (162) (164) ASU 2018-02 transition adjustment (3) - - (3) Net period other comprehensive income (loss) (18) 2 (4) (20) Balance, September 30, 2018 $ (33) $ (7) $ (166) $ (206) T h e followin g tabl e present s th e details of the reclassifications from AOCI fo r th e three and nine months ended September 30, 2018 and 2017 : In millions Amounts Reclassified from AOCI Three Months Ended September 30, Nine Months Ended September 30, Details about AOCI Components 2018 2017 2018 2017 Affected Line Item on the Consolidated Statements of Operations Unrealized gains (losses) on AFS securities: Realized gains (losses) on sale of securities $ 2 $ - $ 4 $ 6 Net gains (losses) on financial instruments at fair value and foreign exchange OTTI (2) (4) (3) (6) Net investment losses related to OTTI Amortization on securities - (1) (1) (2) Net investment income - (5) - (2) Income (loss) before income taxes - - - (1) Provision (benefit) for income taxes Total reclassifications for the period $ - $ (5) $ - $ (1) Net income (loss)

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
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Commitments and Contingencies	Note 13: Commitments and Contingencies The following commitments and contingencies provide an update of those discussed in “Note 2 0 : Commitments and Contingencies” in the Notes to Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 , and should be read in conjunction with the complete descriptions provided in the aforementioned Form 10-K. Litigation MBIA Insurance Corp. v. Credit Suisse Securities (USA) LLC, et al. ; Index No. 603751/2009 (N.Y. Sup. Ct., N.Y. County) On September 13, 2018, the Appellate Division of the Supreme Court, First Judicial Department issued a ruling on the parties’ cross-appeals from the court’s March 31, 2017 decision and order on the parties’ summary judgment motions. The rulin g affirmed the trial court’s decision, except reversed as to the trial court’s determination to interpret as a matter of law, prior to trial, certain of the representations and warranties that form the predicate for certain of MBIA Corp.’s breach of contra ct claims. In May of 2018, Justice Kornreich, who had presided over the above-captioned case since its inception, retired from the bench. On May 25, 2018, Justice Schecter was assigned to be the new presiding justice. A pretrial conference has been schedul ed for February 7, 2019. Ambac Bond Insurance Coverage Cases, Coordinated Proceeding Case No. JCCP 4555 (Super. Ct. of Cal., County of San Francisco) Following a n appeal of the dismissal of the plaintiff’s anti-trust claim under California’s Cartwright Act , the California Court of Appeal reinstated those claims against the bond insurer defendants on February 18 , 201 6 . On December 11, 2017, the parties reached a settlement of the litigation, which has been implemented by the parties and the cases have been d ismissed with prejudice. Lynn Tilton and Patriarch Partners XV, LLC v. MBIA Inc. and MBIA Insurance Corp. v. ; Index No.68880/2015 (N.Y. Sup. Ct., County of Westchester) On November 2, 2015, Lynn Tilton and Patriarch Partners XV, LLC filed a complaint in New York State Supreme Court, Westchester County, against MBIA Inc. and MBIA Corp., alleging fraudulent inducement and related claims arising from purported promises made in connection with insurance policies issued by MBIA Corp. on certain collateralized loan obligations managed by Ms. Tilton and affiliated Patriarch entities, and seeking damages. The plaintiffs filed an amended complaint on January 15, 2016. On December 2 7, 2016, Justice Scheinkman granted in part and denied in part MBIA’s motion to dismiss. On January 17, 2017, MBIA filed its answer. Discovery concluded in October 2017 and a Trial Readiness Conference was held on November 3, 2017, at which the Court set a schedule for the briefing of summary judgment motions, which was completed as of February 1, 2018 and a decision on which is now pending. On January 8, 2018, Justice Walsh was assigned to the case. On March 11, 2018, Ms. Tilton commenced the Zohar Funds B ankruptcy Cases. On May 21, 2018, the court approved the Zohar Bankruptcy Settlement. Subsequently, the parties to the above-captioned litigation jointly filed a request to stay the case for, at minimum, fifteen months, which was granted by Justice Walsh o n June 11, 2018. National Public Finance Guarantee Corporation v. Padilla, Civ. No. 16-cv-2101 (D.P.R. June 15, 2016) (Besosa, J.) On June 15, 2016, National filed a complaint in federal court in Puerto Rico challenging the Puerto Rico Emergency Moratorium and Financial Rehabilitation Act (Law 21-2016 or the “Moratorium Act”) as unconstitutional under the United States Constitution. On June 22, 2016, National filed a motion for partial summary judgment on its claim that the Moratorium Act is preempted by th e federal Bankruptcy Code. On July 7, 2016, the Puerto Rico defendants filed a motion to stay the case pursuant to PROMESA, which was granted by the Court in August of 2016 . The defendants filed their answer to the c omplaint on July 26, 2016. On November 1 5, 2016, the District Court denied National’s motion to lift the litigation stay granted pursuant to PROMESA and on January 30, 2017, the District Court denied National’s partial motion for a summary judgment without prejudice. On January 11, 2017, the U.S . Court of Appeals for the First Circuit affirmed the denial of a separate plaintiff’s motion to lift the PROMESA stay in a related action challenging the Moratorium Act. Accordingly, the case remained stayed through May 1, 2017, at which time the PROMESA stay expired. However, on May 3, 2017, Puerto Rico filed a Title III petition under PROMESA, thereby staying this dispute under Section 405(e) of PROMESA. On August 1, 2017, the District Court dismissed the case with prejudice. On August 28, 2017, National filed a motion for reconsideration. Assured Guaranty Corp. et al. v. Commonwealth of Puerto Rico et al., Case No. 3:17-cv-01578 (D.P.R. May 3, 2017) (Swain, J.) On May 3, 2017, the Financial Oversight and Management Board filed a petition under Title III of PROMESA to adjust the debts of Puerto Rico. On the same day, National, together with Assured Guaranty Corp. and Assured Guaranty Municipal Corp., filed an adversary complaint in the case commenced by the Title III filing, alleging that the Fiscal Plan a nd the Fiscal Plan Compliance Act, signed into law by the Governor of Puerto Rico on April 29, 2017, violate PROMESA and the United States Constitution. On October 6, 2017, National, together with the other plaintiffs in the filing, voluntarily dismissed t he complaint without prejudice. The Bank of New York Mellon v. Puerto Rico Sales Tax Financing Corporation, et al. , Case No. 17-133-LTS (D.P.R. May 16, 2017) (Swain, J.) On May 16, 2017, the Bank of New York Mellon, as trustee for COFINA, filed an adversary complaint seeking an interpleader and declaratory relief relating to conflicting directions from multiple stakeholders regarding alleged events of default. National has intervened in this matter. Given the complexity of the issues, the judge granted Bank of New York’s interpleader request ordering a freeze on disbursements to all bondholders and temporarily setting aside the funds until the dispute can be resolved betwee n the parties. Motions for summary judgment were fully briefed as of January 5, 2018. On September 27, 2018, the Court, sua sponte , entered an order terminating the pending summary judgment motions without prejudice to restoration of the motions on or afte r October 1, 2018. Assured Guaranty Corp. et al. v. Commonwealth of Puerto Rico et al. , Case No. 17 BK 3567-LTS (D.P.R. June 3, 2017) (Swain, J.) On May 2 1 , 2017, the Oversight Board filed a petition under Title III of PROMESA to adjust the debts for the P uerto Rico Highways & Transportation Authority (“PRHTA”). On June 3, 2017, National, together with Assured Guaranty Corp. and Assured Guaranty Municipal Corp. and Financial Guaranty Insurance Company, filed an adversary complaint in the case commenced by t he Title III filing, alleging that the Commonwealth and PRHTA are unlawfully diverting pledged special revenues from the payment of certain PRHTA bonds to the Commonwealth’s General Fund. Motions to dismiss were filed on June 28, 2017, and oral arguments w ere heard on November 21, 2017. On January 30, 2018, the court granted the Commonwealth defendants’ motion to dismiss the PRHTA-related adversary complaint. On February 9, 2018, National, together with Assured, Assured Guaranty Municipal Corp. and Financia l Guaranty Insurance Company filed their notice of appeal of the motions to dismiss to the United States Court of Appeals for the First Circuit. Appellants filed their opening brief on May 9, 2018, and Appellees filed their opposition brief on July 9, 2018 . Appellants’ reply brief was filed on August 8, 2018. O ral argument was held on November 5, 2018. National Public Finance Guarantee Corp. et al. v. The Financial Oversight and Mgmt. Bd. et al. , Case No. 3:17-cv-01882 (D.P.R. June 26, 201 7) (Besosa, J.) On June 26, 2017, National, together with Assured Guaranty Corp. and Assured Guaranty Municipal Corp., filed a complaint against the Oversight Board, its chairman and certain of its members seeking declaratory, injunctive and mandamus relief requiring the Oversight Board to comply with certain of its obligations under PROMESA. On July 17, 2017, National, again joined by Assured Guaranty Corp. and Assured Guaranty Municipal Corp., filed an amended complaint against the Oversight Board, its chairman, and cert ain of its members in their official and individual capacities, seeking declaratory relief under PROMESA and asserting a claim for nominal damages against the individual defendants for tortious interference with the PREPA Restructuring Support Agreement. B y order of the Court dated August 7, 2017, the litigation was stayed. The Financial Oversight and Management Board for Puerto Rico, as representative of The Puerto Rico Electric Power Authority, et al. , Case No. 17 BK 4780-LTS (D.P.R. July 19, 2017) (Swa in, J.) On July 18, 2017, National, together with other PREPA bondholders, asked the court overseeing PREPA’s Title III bankruptcy proceeding to lift the automatic bankruptcy stay, and permit bondholders to seek appointment of a receiver to oversee PREPA. On September 14, 2017, the court held that PROMESA barred relief from the stay because the appointment of a receiver would (i) interfere with PREPA’s property and governmental powers, and (ii) violate the court’s exclusive jurisdiction over PREPA’s propert y. The court also held that a comparison of the harms facing both parties pointed towards denying relief from the stay. The bondholders appealed the decision to the First Circuit. As of April 23, 2018, the appeal was fully briefed. The First Circuit heard oral argument on June 5, 2018. On August 8, 2018, the United State Court of Appeals for the First Circuit issued an order reversing Judge Swain’s decision on jurisdictional grounds and remanding the motion. On October 3, 2018, National, together with Assu red Guaranty Corp., Assured Guaranty Municipal Corp., and Syncora Guarantee Inc. (collectively, “Movants”) filed a n updated motion for relief from the automatic stay to allow Movants to exercise their statutory right to have a receiver appointed at PREPA. D iscovery in connection with Movants’ motion is ongoing. National Public Finance Guarantee Corp. et al. v. The Financial Oversight and Mgmt. Bd. et al., Case No. 17 BK-04780 (D.P.R. August 7, 2017) (Swain, J.) On August 7, 2017, National, together with Assu red Guaranty Corp., Assured Guaranty Municipal Corp., f/k/a Financial Security Assurance Inc., National Public Finance Guarantee Corporation, the Ad Hoc Group of PREPA Bondholders, and Syncora Guarantee Inc. filed an adversary complaint under Title III of PROMESA against PREPA, Financial Oversight and Management Board for Puerto Rico, Puerto Rico Fiscal Agency and Financial Advisory Authority, et al to enforce Plaintiffs’ contractual interest and constitutional right to revenues that PREPA pledged to bondh olders but has thus far refused to turn over. Plaintiffs seek a declaration that Defendants have violated sections 922(d) and 928(a) of the Bankruptcy Code, and that efforts to compel Defendants to apply such revenues to pay for debt service on the Bonds a re not stayed as provided under section 922(d) of the Bankruptcy Code. Plaintiffs also seek a declaration that, pursuant to sections 922(d) and 928 of the Bankruptcy Code as incorporated into PROMESA, PREPA is only authorized to use Revenues to pay for cur rent operating expenses in the current time period, not for future expenses that may be deferred to or payable at a later date. In addition to declaratory relief, Plaintiffs also seek injunctive relief prohibiting Defendants from taking or causing to be ta ken any action that would further violate sections 922(d) and 928(a) of the Bankruptcy Code and ordering Defendants to remit Revenues for the uninterrupted and timely payment of debt service on the Bonds in accordance with sections 922(d) and 928(a) of the Bankruptcy Code. On October 13, 2017, National, together with the other plaintiffs in the filing, voluntarily dismissed without prejudice the above referenced adversary complaint. The Official Committee of Unsecured Creditors of the Commonwealth of Puert o Rico, as agent for the Commonwealth of Puerto Rico v. Bettina Whyte, as agent of the Puerto Rico Sales Tax Financing Corporation, Adv. Pro c. No. 17-257-LTS in Case No. 17 BK 3283-LTS (D.P.R. Sept. 8, 2017) On August 10, 2017, the Court approved and entered a Stipulation and Order Approving Procedure to Resolve Commonwealth-COFINA Dispute in the PROMESA Title III proceeding relating to whether sales and use taxes purportedly pledged by COFINA to secure debt are property of the Commonwealth or COFINA u nder applicable law. On November 16, 2017, National intervened as a Defendant in the adversary proceeding and filed its answer, affirmative defenses, and counterclaims. On December 21, 2017, the Court issued an order, which, inter alia, dismissed without p rejudice, certain claims of the intervenors that exceeded the scope of the Commonwealth-COFINA dispute including certain of National's counterclaims. National’s first counterclaim which seeks a declaratory judgment that the COFINA statutes are constitution al remains a part of this litigation. On January 13, 2018, the Court permitted the Commonwealth Agent to file a second amended complaint. National’s answer was filed on January 30, 2018. The parties filed opening motions for summary judgment on February 21 , 2018, opposition briefs on March 14, 2018, and reply briefs on March 21, 2018. National joined each of the COFINA Agent’s summary judgment filings. On February 26, 2018, the COFINA Agent filed a motion to certify questions of Puerto Rico law regarding CO FINA to the Supreme Court of Puerto Rico. On April 4, 2018, National, along with Ambac Assurance Corporation, filed a limited objection to the COFINA Agent’s certification motion. On April 10, 2018, the Court heard oral argument on motions for summary judg ment after which it took the matter under advisement. On May 14, 2018, the Oversight Board and the Puerto Rico Fiscal Agency and Financial Advisory Authority rejected a settlement proposal by COFINA and GO bondholders. On May 24, 2018, the Court denied the COFINA Agent’s motion to certify questions of Puerto Rico law regarding COFINA to the Supreme Court of Puerto Rico. On June 5, 2018, the Commonwealth and COFINA Agents submitted a Joint Urgent Motion, which disclosed their agreement in principle to settle the Commonwealth-COFINA Dispute and related issues under the Agents’ mediation authority. Under the proposed settlement terms, COFINA and the Commonwealth would agree to share the statutory Pledged Sales Tax Base Amount. COFINA would receive (a) 53.65 % of the yearly scheduled Pledged Sales Tax Base Amount (beginning with payments made on July 1, 2018), and (b) 100 % of the funds on deposit prior to July 1, 2018 in the debt service accounts held by the Bank of New York Mellon . COFINA’s T itle III plan of adjustment would provide that, to the exte nt permitted under applicable law, all restructured securities issued by reorganized COFINA (or a new entity established pursuant to COFINA’s Title III plan of adjustment) would be tax-exempt, with the COFINA Agent. On June 11, 2018, the Court issued an or der holding its decision on the motions for summary judgment in abeyance for a 60-day period in light of the parties’ progression towards settlement. The abeyance period was extended several times to accommodate ongoing negotiations to resolve the Commonwe alth-COFINA dispute. The Title III Court has scheduled a hearing to confirm a plan of adjustment in the COFINA case for January 16, 201 9 . For those aforementioned actions in which it is a defendant, t he Company is defending against th os e actions and expect s ultimately to prevail on the merits. There is no assurance, however, that the Company will prevail in these actions. Adverse rulings in these actions could have a material adverse effect on the Company’s ability to implement its strategy and on its busin ess, results of operations, cash flows and financial condition. At this stage of the litigation, there has not been a determination as to the amount, if any, of damages. Accordingly, the Company is not able to estimate any amount of loss or range of loss. The Company similarly can provide no assurance that it will be successful in those actions in which it is a plaintiff. There are no other material lawsuits pending or, to the knowledge of the Company, threatened, to which the Company or any of its subsidia ries is a party . Lease Commitments The Company has a lease agreement for its headquarters in Purchase, New York as well as other immaterial leases for offices in New York, New York and San Francisco, California. The Purchase, New York initial lease term e xpires in 2030 with the option to terminate the lease in 2025 upon the payment of a termination amount. This lease agreement included an incentive amount to fund certain leasehold improvements, renewal options, escalation clauses and a free rent period. Th is lease agreement has been classified as an operating lease, and operating rent expense has been recognized on a straight-line basis since the second quarter of 2014 . As of September 30, 2018 , total future minimum lease payments remaining on this lease were $ 34 million .

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Subsequent Events	Note 14: Subsequent Events Re f e r t o “ Note 13: Commitments and Contingencies ” f o r in f o rm a t i o n a bou t l e ga l p r o c eed i ng s t ha t o cc u rr e d a f t e r September 30, 2018 .

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited consolidated financial statements have been prepared in accordance with the instructions to Fo rm 10-Q and Article 10 of Regulation S-X and, accordingly, do not include all of the information and disclosures required by accounting principles generally accepted in the United States of America (“ GAAP ”) for annual periods. These statements should be re ad in conjunction with the consolidated financial statements and notes thereto included in the Annual Report on Form 10-K for the year ended December 31, 2017 . The accompanying consolidated financial statements have not been audited by an independent re gistered public accounting firm in accordance with the standards of the Public Company Accounting Oversight Board (U.S.), but in the opinion of management such financial statements include all adjustments, consisting only of normal recurring adjustments, n ecessary for the fair statement of the Company’s consolidated financial position and results of operations. All material intercompany balances and transactions have been eliminated. The preparation of financial statements requires management to make estima tes and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actu al results could differ from those estimates. As additional information becomes available or actual amounts become determinable, the recorded estimates are revised and reflected in operating results. The results of operations for the three and nine months ended September 30, 2018 may not be indicative of the results that may be expected for the year ending December 31, 2018 . The December 31, 2017 consolidated balance sheet was derived from audited financial statements, but does not include all disclosures requi red by GAAP for annual periods. Certain amounts have been reclassified in the prior year’s financial statements to conform to the current presentation. This includes a change in the classification of certain cash receipts and cash payments on the Company’s consolidated statement of cash flows as required under Accounting Standards Update (“ASU”) 2016- 15 , “ Statement of Cash Flows (Topic 230 )”. This classification change a ffected “Interest paid, net of interest converted to principal”, in operating cash flows , and “Principal paydowns of investment agreements ” and “Principal paydowns of medium-term notes”, in financing cash flows, on the Company’s consolidated statement of cash flows for the prior period. Such reclassifications did not materially impact total r evenues, expenses, assets, liabilities, shareholders’ equity, operating cash flows, investing cash flows, or financing cash flows for all periods presented . During the third quarter of 2018, the Company corrected an error related to the second quarter of 2 018 of $ 3 million and an error related to the first quarter of 2017 of $ 3 million, which, in aggregate, reduced the third quarter of 2018’s net loss by $ 6 million. The first quarter of 2017 error related to a gain of the extinguishment of debt and the second quarter of 2018 error related to a benefit on losses and loss adjustment expense. The Company evaluated the materiality of these errors in accordance with Securities and Exch ange Commission (“SEC”) Staff Accounting Bulletin No. 99, Materiality, and SEC Staff Accounting Bulletin No. 108, Considering the Effects of Prior Year Misstatements When Quantifying Misstatements in Current Year Financial Statements, and concluded that th ese errors, individually and in the aggregate, were immaterial to the three months ended September 30, 2018 and the prior periods to which these errors relate.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards Revenue from Contracts with Customers (Topic 606) (ASU 2014-09) and Deferral of the Effective Date (ASU 201 5 - 14 ) In May of 2014, the Financial Accounting Standards Board (“FASB”) issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 amends the accounting guidance for recognizing revenue for the transfer of goods or services from contracts with customers unless those contracts are within the scope of other accounting stan dards. ASU 2014-09 does not apply to financial guarantee insurance contracts within the scope of Topic 944, “Financial Services — Insurance.” In August of 2015, the FASB issued ASU 2015-14, “Revenue from Contracts with Customers (Topic 606) — Deferral of t he Effective Date. ” ASU 2015-14 defers the effective date of ASU 2014-09 to interim and annual periods beginning January 1, 2018, and is applied on a retrospective or modified retrospective basis. The Company adopted ASU 2014-09 in the first quarter of 201 8 and the adoption of ASU 2014-09 did not affect the Company’s consolidated financial statements. Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (ASU 2016-01) In January of 2016, t he FASB issued ASU 2016-01, “Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities.” ASU 2016-01 requires certain equity investments other than those accounted for under the equity method of accounting or result in consolidation of the investee to be measured at fair value with changes in fair value recognized in net income, and permits an entity to measure equity investments that do not have readily determinable fair values at cost less a ny impairment plus or minus adjustments for certain changes in observable prices. An entity is also required to evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale (“AFS”) debt securities in combination with th e entity’s other deferred tax assets. ASU 2016-01 requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability that results from a change in the instrument-specific credit risk for financial liabilities that the entity has elected to measure at fair value in accordance with the fair value option for financial instruments. ASU 2016-01 wa s effective for interim and annual periods beginning January 1, 2018 . As such, the Company reclasse d a loss of $ 162 million from retained earnings to accumulated other comprehensive income (“AOCI”) related to the instrument-specific credit risk portion of financial liabilities measured at fair value in accordance with the fair value option. In addition, the Company reclassed net unrealized gains of $ 2 million from AOCI to retained earnings related to equity investments. As of September 30, 2018 and December 31, 2017 , the Company had a full valuation allowance against its deferred tax asset. Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income (ASU 2018-02) In February of 2018, the FASB issued ASU 2018-02, “Income Statement – Reporting Comprehensive Income ( Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” ASU 2018-02 permits, but does not require, the reclassification of the income tax effects of the Tax Cuts and Jobs Act (the “Act”) from AOCI to retained earni ngs. ASU 2018-02 is effective for interim and annual periods beginning after December 15, 2018. Early adoption of ASU 2018-02 is permitted and is applied in the period of adoption or retroactively to each period in which the effect of the change in the U.S . federal corporate income tax rate in the Act is recognized. The Company adopted ASU 2018-02 in the first quarter of 2018. As such, the Company reclassed income taxes of $ 3 million from AOCI to retained earnings. The Company’s accounting policy related to releasing income tax effects that are lodged in AOCI is on a portfolio approach basis. The Company has not adopted any other new accounting pronouncements that had a material impact on its consolidated financial statements.
New Accounting Pronouncements Not Yet Adopted	Recent Accounting Developments Leases (Topic 842) (ASU 2016-02) In February of 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)” , that amends the accounting guidance for leasing transactions. ASU 2016-02 requires a lessee to classify lease contracts as finance or operating lease s, and to recognize assets and liabilities for the rights and obligations created by leasing transactions with lease terms more than twelve months. ASU 2016-02 substantially retains the criteria for classifying leasing transactions as finance or operating leases. For finance leases, a lessee recognizes a right-of-use asset and a lease liability initially measured at the present value of the lease payments, and recognizes interest expense on the lease liability separately from the amortization of the right-o f-use asset. For operating leases, a lessee recognizes a right-of-use asset and a lease liability initially measured at the present value of the lease payments, and recognizes lease expense on a straight-line basis. ASU 2016-02 is effective for interim and annual periods beginning January 1, 2019 with early adoption permitted, and is applied on a modified retrospective basis. The Company is currently evaluating its lease commitments and expects an increase in its total assets and total liabilities on its con solidated balance sheet reflecting the recognition of its right-of-use asset and lease liability, respectively. The gross up of the assets and liabilities is expected to have no impact on the Company’s statement of operations. Refer to “Note 13: Commitments and Continge ncies” for information about the Company’s lease commitments. Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13) In June of 2016, the FASB issued ASU 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” ASU 2016-13 requires financing receivables and other financial assets measured at amortized cost to be presented at the net amount expected to be collected by recording an allowanc e for credit losses with changes in the allowance recorded as credit loss expense or reversal of credit loss expense based on management’s current estimate of expected credit losses each period. ASU 2016-13 does not apply to credit losses on financial guar antee insurance contracts within the scope of Topic 944, “Financial Services-Insurance.” ASU 2016-13 also requires impairment relating to credit losses on AFS debt securities to be presented through an allowance for credit losses with changes in the allowa nce recorded in the period of the change as credit loss expense or reversal of credit loss expense. Any impairment amount not recorded through an allowance for credit losses on AFS debt securities is recorded through other comprehensive income. ASU 2016-13 is effective for interim and annual periods beginning January 1, 2020 with early adoption permitted beginning January 1, 2019. ASU 2016-13 is applied on a modified retrospective basis except that prospective application is applied to AFS debt securities w ith other-than-temporary impairments (“OTTI”) recognized before the date of adoption. The Company is evaluating the impact of adopting ASU 2016-13 . Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Va lue Measurement (ASU 2018-13) In August of 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement.” ASU 2018-13 modifies the disclosure requirements on fair value measurements. ASU 2018-13 is effective for interim and annual periods beginning January 1, 2020 with early adoption permitted to remove or modify disclosures upon issuance of the standard and delay adoption of the additional disclosures until th e effective date. Upon the effective date, certain amendments should be applied prospectively, while others are to be applied retrospectively to all periods presented. The Company is evaluating the impact of adopting ASU 2018-13. Since the amendments of AS U 2018-13 only impact disclosure requirements, the Company does not expect the adoption of ASU 2018-13 to have an impact on its consolidated financial statements.

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2018
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Summary Of Nonconsolidated VIEs Assets And Liabilities	September 30, 2018 Carrying Value of Assets Carrying Value of Liabilities Loss and Loss Maximum Unearned Adjustment VIE Exposure Premiums Insurance Loss Premium Expense In millions Assets to Loss Investments (1) Receivable (2) Recoverable (3) Revenue (4) Reserves (5) Insurance: Global structured finance: Mortgage-backed residential $ 5,879 $ 3,251 $ 18 $ 20 $ 143 $ 18 $ 356 Mortgage-backed commercial 131 59 - - - - - Consumer asset-backed 4,514 586 - 2 1 1 10 Corporate asset-backed 3,854 1,377 - 9 839 11 10 Total global structured finance 14,378 5,273 18 31 983 30 376 Global public finance 15,058 2,296 - 9 - 12 - Total insurance $ 29,436 $ 7,569 $ 18 $ 40 $ 983 $ 42 $ 376 __________ (1) - Reported within "Investments" on MBIA's consolidated balance sheets. (2) - Reported within "Premiums receivable" on MBIA's consolidated balance sheets. (3) - Reported within "Insurance loss recoverable" on MBIA's consolidated balance sheets. (4) - Reported within "Unearned premium revenue" on MBIA's consolidated balance sheets. (5) - Reported within "Loss and loss adjustment expense reserves" on MBIA's consolidated balance sheets. December 31, 2017 Carrying Value of Assets Carrying Value of Liabilities Loss and Loss Maximum Unearned Adjustment VIE Exposure Premiums Insurance Loss Premium Expense In millions Assets to Loss Investments (1) Receivable (2) Recoverable (3) Revenue (4) Reserves (5) Insurance: Global structured finance: Mortgage-backed residential $ 7,295 $ 3,741 $ 19 $ 22 $ 172 $ 20 $ 396 Mortgage-backed commercial 216 94 - - - - - Consumer asset-backed 5,010 981 - 4 1 3 10 Corporate asset-backed 2,418 1,645 - 13 - 14 - Total global structured finance 14,939 6,461 19 39 173 37 406 Global public finance 15,568 2,524 - 10 - 14 - Total insurance $ 30,507 $ 8,985 $ 19 $ 49 $ 173 $ 51 $ 406 __________ (1) - Reported within "Investments" on MBIA's consolidated balance sheets. (2) - Reported within "Premiums receivable" on MBIA's consolidated balance sheets. (3) - Reported within "Insurance loss recoverable" on MBIA's consolidated balance sheets. (4) - Reported within "Unearned premium revenue" on MBIA's consolidated balance sheets. (5) - Reported within "Loss and loss adjustment expense reserves" on MBIA's consolidated balance sheets.

Loss and Loss Adjustment Expe_2

Loss and Loss Adjustment Expense Reserves (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Present Value Of The Probability-Weighted Future Claim Payments And Recoveries	As of September 30, 2018 As of December 31, 2017 In millions Balance Sheet Line Item Balance Sheet Line Item Insurance loss recoverable Loss and LAE reserves Insurance loss recoverable Loss and LAE reserves U.S. Public Finance Insurance $ 554 $ 634 $ 333 $ 512 International and Structured Finance Insurance: Before VIE eliminations (1) 1,457 628 1,478 710 VIE eliminations (1) (469) (229) (1,300) (243) Total international and structured finance insurance 988 399 178 467 Total $ 1,542 $ 1,033 $ 511 $ 979 _________________ (1) - Includes loan repurchase commitments of $415 million and $407 million as of September 30, 2018 and December 31, 2017, respectively.
Schedule Of Loss And Loss Adjustment Expenses Reserves	In millions Changes in Loss and LAE Reserves for the Nine Months Ended September 30, 2018 Gross Loss Gross Loss and LAE Accretion Changes in and LAE Reserves as of of Claim Changes in Unearned Changes in Reserves as of December 31, Loss Liability Discount Changes in Premium LAE September 30, 2017 Payments Discount Rates Assumptions Revenue Reserves Other (1) 2018 $ 979 $ (344) $ 18 $ 25 $ 336 $ 12 $ 8 $ (1) $ 1,033 ____________ (1) - Primarily changes in amount and timing of payments.
Schedule Of Insurance Loss Recoverable And Changes In Recoveries On Unpaid Losses	Changes in Insurance Loss Recoverable and Recoveries on Unpaid Losses for the Nine Months Ended September 30, 2018 Gross Gross Reserve Reserve as of Accretion Changes in Changes in as of December 31, Collections of Discount Changes in LAE September 30, In millions 2017 for Cases Recoveries Rates Assumptions Recoveries Other (1) 2018 Insurance loss recoverable $ 511 $ (42) $ 14 $ (29) $ 1,084 (2) $ - $ 4 $ 1,542 Recoveries on unpaid losses (3) 35 - 1 (1) (8) (6) - 21 Total $ 546 $ (42) $ 15 $ (30) $ 1,076 $ (6) $ 4 $ 1,563 ____________ (1) - Primarily changes in amount and timing of collections. (2) - Includes amounts which have been paid and are expected to be recovered in the future. (3) - As of September 30, 2018 and December 31, 2017, excludes Puerto Rico recoveries which have been netted against reserves.
Schedule Of Financial Guarantees And Related Claim Liability	Surveillance Categories Caution Caution Caution List List List Classified $ in millions Low Medium High List Total Number of policies 56 20 - 243 319 Number of issues (1) 16 6 - 109 131 Remaining weighted average contract period (in years) 7.2 8.0 - 9.7 9.0 Gross insured contractual payments outstanding: (2) Principal $ 1,933 $ 262 $ - $ 5,465 $ 7,660 Interest 2,314 131 - 5,443 7,888 Total $ 4,247 $ 393 $ - $ 10,908 $ 15,548 Gross Claim Liability (3) $ - $ - $ - $ 1,076 $ 1,076 Less: Gross Potential Recoveries (4) - - - 2,058 2,058 Discount, net (5) - - - (483) (483) Net claim liability (recoverable) $ - $ - $ - $ (499) $ (499) Unearned premium revenue $ 6 $ 4 $ - $ 65 $ 75 Reinsurance recoverable on paid and unpaid losses (6) $ 23 __________ (1) - An “issue” represents the aggregate of financial guarantee policies that share the same revenue source for purposes of making debt service payments on the insured debt. (2) - Represents contractual principal and interest payments due by the issuer of the obligations insured by MBIA. (3) - The gross claim liability with respect to Puerto Rico exposures are net of expected recoveries for policies in a net payable position. (4) - Gross potential recoveries with respect to certain Puerto Rico exposures are net of the claim liability for policies in a net recoverable position. (5) - Represents discount related to Gross Claim Liability and Gross Potential Recoveries. (6) - Included in "Other assets" on the Company's consolidated balance sheets. Surveillance Categories Caution Caution Caution List List List Classified $ in millions Low Medium High List Total Number of policies 89 5 1 280 375 Number of issues (1) 20 4 1 119 144 Remaining weighted average contract period (in years) 7.4 4.3 8.7 9.7 8.9 Gross insured contractual payments outstanding: (2) Principal $ 2,764 $ 13 $ 104 $ 6,083 $ 8,964 Interest 2,676 3 46 5,756 8,481 Total $ 5,440 $ 16 $ 150 $ 11,839 $ 17,445 Gross Claim Liability (3) $ - $ - $ - $ 1,082 $ 1,082 Less: Gross Potential Recoveries (4) - - - 782 782 Discount, net (5) - - - (178) (178) Net claim liability (recoverable) $ - $ - $ - $ 478 $ 478 Unearned premium revenue $ 9 $ - $ 4 $ 77 $ 90 Reinsurance recoverable on paid and unpaid losses (6) $ 17 __________ (1) - An “issue” represents the aggregate of financial guarantee policies that share the same revenue source for purposes of making debt service payments on the insured debt. (2) - Represents contractual principal and interest payments due by the issuer of the obligations insured by MBIA. (3) - The gross claim liability with respect to Puerto Rico exposures are net of expected recoveries for policies in a net payable position. (4) - Gross potential recoveries with respect to certain Puerto Rico exposures are net of the claim liability for policies in a net recoverable position. (5) - Represents discount related to Gross Claim Liability and Gross Potential Recoveries. (6) - Included in "Other assets" on the Company's consolidated balance sheets.

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Quantitative Information Regarding The Significant Unobservable Inputs For Certain Assets And Liabilities Measured At Fair Value On A Recurring Basis	Fair Value as of Range September 30, (Weighted In millions 2018 Valuation Techniques Unobservable Input Average) Assets of consolidated VIEs: Loans receivable at fair value $ 428 Market prices adjusted for financial Impact of financial guarantee (1) -18% - 63% (-5%) guarantees provided to VIE obligations Loan repurchase commitments 415 Discounted cash flow Recovery rates (2) Breach rates (2) Liabilities of consolidated VIEs: Variable interest entity notes 382 Market prices of VIE assets adjusted for Impact of financial guarantee 0% - 65% (40%) financial guarantees provided Credit derivative liabilities: CMBS 27 Direct Price Model Nonperformance risk 54% - 54% (54%) Other derivative liabilities 7 Discounted cash flow Cash flows $0 - $49 ($25) (3) ____________ (1) - Negative percentage represents financial guarantee policies in a receivable position. (2) - Recovery rates and breach rates include estimates about potential variations in the outcome of litigation with a counterparty. (3) - Midpoint of cash flows are used for the weighted average. Fair Value as of Range December 31, (Weighted In millions 2017 Valuation Techniques Unobservable Input Average) Assets of consolidated VIEs: Loans receivable at fair value $ 1,679 Market prices adjusted for financial Impact of financial guarantee (1) -25% - 35% (-2%) guarantees provided to VIE obligations Multiples of EBITDA Multiples (2) Loan repurchase commitments 407 Discounted cash flow Recovery rates (3) Breach rates (3) Liabilities of consolidated VIEs: Variable interest entity notes 406 Market prices of VIE assets Impact of financial guarantee 0% - 60% (36%) adjusted for financial guarantees provided Credit derivative liabilities: CMBS 63 Direct Price Model Nonperformance risk 54% - 54% (54%) Other derivative liabilities 4 Discounted cash flow Cash flows $0 - $49 ($25) (4) ____________ (1) - Negative percentage represents financial guarantee policies in a receivable position. (2) - Unobservable inputs are primarily based on comparable companies' EBITDA multiples. (3) - Recovery rates and breach rates include estimates about potential variations in the outcome of litigation with a counterparty. (4) - Midpoint of cash flows are used for the weighted average.
Company's Assets And Liabilities Measured At Fair Value On Recurring Basis	Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Active Markets Other Significant for Identical Observable Unobservable Balance as of Assets Inputs Inputs September 30, In millions (Level 1) (Level 2) (Level 3) 2018 Assets: Fixed-maturity investments: U.S. Treasury and government agency $ 765 $ 89 $ - $ 854 State and municipal bonds - 757 - 757 Foreign governments - 11 - 11 Corporate obligations 20 1,603 - 1,623 Mortgage-backed securities: Residential mortgage-backed agency - 220 - 220 Residential mortgage-backed non-agency - 30 - 30 Commercial mortgage-backed - 50 7 (1) 57 Asset-backed securities: Collateralized debt obligations - 146 - 146 Other asset-backed - 217 4 (1) 221 Total fixed-maturity investments 785 3,123 11 3,919 Money market securities 147 - - 147 Perpetual debt and equity securities 26 38 - 64 Fixed-income fund - - - 75 (2) Cash and cash equivalents 167 - - 167 Derivative assets: Non-insured derivative assets: Interest rate derivatives - 2 - 2 Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Active Markets Other Significant for Identical Observable Unobservable Balance as of Assets Inputs Inputs September 30, In millions (Level 1) (Level 2) (Level 3) 2018 Assets of consolidated VIEs: Corporate obligations - 9 5 (1) 14 Mortgage-backed securities: Residential mortgage-backed non-agency - 98 - 98 Commercial mortgage-backed - 35 - 35 Asset-backed securities: Collateralized debt obligations - 6 1 (1) 7 Other asset-backed - 9 - 9 Cash 12 - - 12 Loans receivable at fair value: Residential loans receivable - - 428 428 Loan repurchase commitments - - 415 415 Other assets: Currency derivatives - - 14 (1) 14 Other - - 15 (1) 15 Total assets $ 1,137 $ 3,320 $ 889 $ 5,421 Liabilities: Medium-term notes $ - $ - $ 123 (1) $ 123 Derivative liabilities: Insured derivatives: Credit derivatives - 2 27 29 Non-insured derivatives: Interest rate derivatives - 137 - 137 Other - - 7 7 Other liabilities: Other payable - - 5 (1) 5 Liabilities of consolidated VIEs: Variable interest entity notes - 327 382 709 Total liabilities $ - $ 466 $ 544 $ 1,010 ____________ (1) - Unobservable inputs are either not developed by the Company or do not significantly impact the overall fair values of the aggregate financial assets and liabilities. (2) - Investment that was measured at fair value by applying the net asset value per share practical expedient, and was required not to be classified in the fair value hierarchy. Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Active Markets Other Significant for Identical Observable Unobservable Balance as of Assets Inputs Inputs December 31, In millions (Level 1) (Level 2) (Level 3) 2017 Assets: Fixed-maturity investments: U.S. Treasury and government agency $ 1,256 $ 96 $ - $ 1,352 State and municipal bonds - 858 - 858 Foreign governments - 10 - 10 Corporate obligations - 1,338 2 (1) 1,340 Mortgage-backed securities: Residential mortgage-backed agency - 368 - 368 Residential mortgage-backed non-agency - 32 - 32 Commercial mortgage-backed - 60 7 (1) 67 Asset-backed securities: Collateralized debt obligations - 118 - 118 Other asset-backed - 178 5 (1) 183 Total fixed-maturity investments 1,256 3,058 14 4,328 Money market securities 180 - - 180 Perpetual debt and equity securities 26 37 - 63 Fixed-income fund - - - 82 (2) Cash and cash equivalents 122 - - 122 Derivative assets: Non-insured derivative assets: Interest rate derivatives - 2 - 2 Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Active Markets Other Significant for Identical Observable Unobservable Balance as of Assets Inputs Inputs December 31, In millions (Level 1) (Level 2) (Level 3) 2017 Assets of consolidated VIEs: Corporate obligations - 19 - 19 Mortgage-backed securities: Residential mortgage-backed non-agency - 108 - 108 Commercial mortgage-backed - 30 6 (1) 36 Asset-backed securities: Collateralized debt obligations - 8 1 (1) 9 Other asset-backed - 10 - 10 Cash 24 - - 24 Loans receivable at fair value: Residential loans receivable - - 759 759 Corporate loans receivable - - 920 920 Loan repurchase commitments - - 407 407 Other assets: Currency derivatives - - 19 (1) 19 Other - - 14 (1) 14 Total assets $ 1,608 $ 3,272 $ 2,140 $ 7,102 Liabilities: Medium-term notes $ - $ - $ 115 (1) $ 115 Derivative liabilities: Insured derivatives: Credit derivatives - 2 63 65 Non-insured derivatives: Interest rate derivatives - 193 - 193 Other - - 4 4 Other liabilities: Warrants - 6 - 6 Other payable - - 7 (1) 7 Liabilities of consolidated VIEs: Variable interest entity notes - 663 406 1,069 Total liabilities $ - $ 864 $ 595 $ 1,459 ____________ (1) - Unobservable inputs are either not developed by the Company or do not significantly impact the overall fair values of the aggregate financial assets and liabilities. (2) - Investment that was measured at fair value by applying the net asset value per share practical expedient, and was required not to be classified in the fair value hierarchy.
Fair Value Hierarchy Table Presents The Company's Assets And Liabilities Not Recorded At Fair Value On The Company's Consolidated Balance Sheet	Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Significant Fair Value Carry Value Active Markets for Other Observable Unobservable Balance as of Balance as of Identical Assets Inputs Inputs September 30, September 30, In millions (Level 1) (Level 2) (Level 3) 2018 2018 Assets: Other investments $ - $ 1 $ - $ 1 $ 1 Assets of consolidated VIEs: Investments held-to-maturity - - 901 901 890 Total assets $ - $ 1 $ 901 $ 902 $ 891 Liabilities: Long-term debt $ - $ 1,132 $ - $ 1,132 $ 2,218 Medium-term notes - - 416 416 615 Investment agreements - - 381 381 314 Liabilities of consolidated VIEs: Variable interest entity notes - 382 900 1,282 1,251 Total liabilities $ - $ 1,514 $ 1,697 $ 3,211 $ 4,398 Financial Guarantees: Gross $ - $ - $ 1,231 $ 1,231 $ 100 Ceded - - 68 68 38 Fair Value Measurements at Reporting Date Using Quoted Prices in Significant Significant Fair Value Carry Value Active Markets for Other Observable Unobservable Balance as of Balance as of Identical Assets Inputs Inputs December 31, December 31, In millions (Level 1) (Level 2) (Level 3) 2017 2017 Assets: Other investments $ - $ 2 $ - $ 2 $ 2 Assets of consolidated VIEs: Investments held-to-maturity - - 916 916 890 Total assets $ - $ 2 $ 916 $ 918 $ 892 Liabilities: Long-term debt $ - $ 1,002 $ - $ 1,002 $ 2,121 Medium-term notes - - 406 406 650 Investment agreements - - 433 433 337 Liabilities of consolidated VIEs: Variable interest entity notes - 352 916 1,268 1,220 Total liabilities $ - $ 1,354 $ 1,755 $ 3,109 $ 4,328 Financial Guarantees: Gross $ - $ - $ 1,785 $ 1,785 $ 1,220 Ceded - - 61 61 39
Changes In Level 3 Assets Measured At Fair Value On A Recurring Basis	Changes in Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis for the Three Months Ended September 30, 2018 Change in Unrealized Gains (Losses) for the Period Included in Unrealized Earnings Gains / Unrealized Foreign for Assets (Losses) Gains / Exchange still held Balance, Realized Included (Losses) Recognized Transfers Transfers as of Beginning Gains / in Included in OCI or into out of Ending September 30, In millions of Period (Losses) Earnings in OCI Earnings Purchases Issuances Settlements Sales Level 3 (1) Level 3 (1) Balance 2018 Assets: Commercial mortgage-backed $ - $ - $ - $ - $ - $ - $ - $ - $ - $ 7 $ - $ 7 $ - Other asset-backed 6 - - - - - - - - - (2) 4 - Assets of consolidated VIEs: Corporate obligations 5 - - - - - - - - - - 5 - Collateralized debt obligations 1 - - - - - - - - - - 1 - Loans receivable- residential 683 - 20 - - - - (24) (251) - - 428 21 Loan repurchase commitments 415 - - - - - - - - - - 415 - Currency derivatives 14 - 2 - (2) - - - - - - 14 - Other 14 - 1 - - - - - - - - 15 1 Total assets $ 1,138 $ - $ 23 $ - $ (2) $ - $ - $ (24) $ (251) $ 7 $ (2) $ 889 $ 22 Changes in Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis for the Three Months Ended September 30, 2017 Change in Unrealized Gains (Losses) for the Period Included in Unrealized Earnings for Gains / Unrealized Foreign Assets (Losses) Gains / Exchange still held Balance, Realized Included (Losses) Recognized Transfers Transfers as of Beginning Gains / in Included in OCI or into out of Ending September 30, In millions of Period (Losses) Earnings in OCI Earnings Purchases Issuances Settlements Sales Level 3 (1) Level 3 (1) Balance 2017 Assets: Commercial mortgage-backed $ 7 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ (7) $ - $ - Other asset-backed 5 - - - - - - - - - - 5 - Assets of consolidated VIEs: Commercial mortgage-backed 3 - - - - - - - (3) - - - - Collateralized debt obligations 1 - - - - - - - - - - 1 - Loans receivable- residential 815 - 2 - - - - (58) - - - 759 2 Loans receivable- corporate 875 - 4 - - - - (6) - - - 873 4 Loan repurchase commitments 407 - (1) - - - - - - - - 406 (1) Currency derivatives 9 - 3 - 1 - - - - - - 13 4 Other - - - - - 17 - - - - - 17 - Total assets $ 2,122 $ - $ 8 $ - $ 1 $ 17 $ - $ (64) $ (3) $ - $ (7) $ 2,074 $ 9 Changes in Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis for the Nine Months Ended September 30, 2018 Change in Unrealized Gains (Losses) for the Period Included in Unrealized Earnings for Gains / Unrealized Foreign Assets (Losses) Gains / Exchange still held Balance, Realized Included (Losses) Recognized Transfers Transfers as of Beginning Gains / in Included in OCI or into out of Ending September 30, In millions of Year (Losses) Earnings in OCI Earnings Purchases Issuances Settlements Sales Level 3 (1) Level 3 (1) Balance 2018 Assets: Corporate obligations $ 2 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ (2) $ - $ - Commercial mortgage-backed 7 - - - - - - - - 7 (7) 7 - Other asset-backed 5 - - - - 5 - (2) (2) - (2) 4 - Assets of consolidated VIEs: Corporate obligations - - - - - - - (1) - 6 - 5 - Commercial mortgage-backed 6 - - - - - - - - - (6) - - Collateralized debt obligations 1 - - - - - - - - - - 1 - Loans receivable- residential 759 - 26 - - - - (106) (251) - - 428 23 Loans receivable- corporate 920 - 11 - - - - (6) (925) - - - - Loan repurchase commitments 407 - 8 - - - - - - - - 415 8 Currency derivatives 19 - (3) - (2) - - - - - - 14 (5) Other 14 - 1 - - - - - - - - 15 1 Total assets $ 2,140 $ - $ 43 $ - $ (2) $ 5 $ - $ (115) $ (1,178) $ 13 $ (17) $ 889 $ 27 Changes in Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis for the Nine Months Ended September 30, 2017 Change in Unrealized Gains (Losses) for the Period Included in Unrealized Earnings for Gains / Unrealized Foreign Assets (Losses) Gains / Exchange still held Balance, Realized Included (Losses) Recognized Transfers Transfers as of Beginning Gains / in Included in OCI or into out of Ending September 30, In millions of Year (Losses) Earnings in OCI Earnings Purchases Issuances Settlements Sales Level 3 (1) Level 3 (1) Balance 2017 Assets: Corporate obligations $ 2 $ - $ - $ - $ - $ - $ - $ - $ - $ - $ (2) $ - $ - Commercial mortgage-backed - - - - - - - - - 7 (7) - - Collateralized debt obligations 15 - - - - - - (7) - - (8) - - Other asset-backed 44 - - 2 - - - (41) - - - 5 - State and municipal bonds - - - - - - - - - 1 (1) - - Assets of consolidated VIEs: Corporate obligations - - - - - - - (2) - 6 (4) - - Commercial mortgage-backed - - - - - - - - (3) 3 - - - Collateralized debt obligations 1 - - - - - - - - - - 1 - Other asset-backed 1 - - - - - - - - 1 (2) - - Loans receivable- residential 916 - 29 - - - - (186) - - - 759 29 Loans receivable- corporate 150 - 36 - - 719 - (32) - - - 873 36 Loan repurchase commitments 404 - 2 - - - - - - - - 406 2 Currency derivatives 19 - (2) - (4) - - - - - - 13 (6) Other - - - - - 17 - - - - - 17 - Total assets $ 1,552 $ - $ 65 $ 2 $ (4) $ 736 $ - $ (268) $ (3) $ 18 $ (24) $ 2,074 $ 61
Changes In Level 3 Liabilities Measured At Fair Value On A Recurring Basis	Change in Unrealized (Gains) Losses for the Period Included in Unrealized Unrealized Earnings for (Gains) / (Gains) / Foreign Liabilities Losses Losses Exchange still held Balance, Realized Included Included in Recognized Transfers Transfers as of Beginning (Gains) / in Credit Risk in OCI or into out of Ending September 30, In millions of Period Losses Earnings in OCI Earnings Purchases Issuances Settlements Sales Level 3 (1) Level 3 (1) Balance 2018 Liabilities: Medium-term notes $ 149 $ (5) $ (1) $ 11 $ (1) $ - $ - $ (30) $ - $ - $ - $ 123 $ (2) Credit derivatives 31 6 (4) - - - - (6) - - - 27 (4) Other derivatives 4 - 3 - - - - - - - - 7 3 Other payable 5 - - - - - - - - - - 5 - Liabilities of consolidated VIEs: VIE notes 389 10 3 (11) 5 - 1 (15) - - - 382 8 Total liabilities $ 578 $ 11 $ 1 $ - $ 4 $ - $ 1 $ (51) $ - $ - $ - $ 544 $ 5 _______________ (1) - Transferred in and out at the end of the period. Change in Unrealized (Gains) Losses for the Period Included in Unrealized Earnings for (Gains) / Unrealized Foreign Liabilities Losses (Gains) / Exchange still held Balance, Realized Included Losses Recognized Transfers Transfers as of Beginning (Gains) / in Included in OCI or into out of Ending September 30, In millions of Period Losses Earnings in OCI Earnings Purchases Issuances Settlements Sales Level 3 (1) Level 3 (1) Balance 2017 Liabilities: Medium-term notes $ 123 $ - $ (1) $ - $ 5 $ - $ - $ - $ - $ - $ - $ 127 $ 4 Credit derivatives 80 7 (6) - - - - (7) - - - 74 (6) Other derivatives 4 - - - - - - - - - - 4 - Other payable - - 1 - - 6 - - - - - 7 1 Liabilities of consolidated VIEs: VIE notes 491 - 4 - - - - (14) (51) - - 430 4 Total liabilities $ 698 $ 7 $ (2) $ - $ 5 $ 6 $ - $ (21) $ (51) $ - $ - $ 642 $ 3 _______________ (1) - Transferred in and out at the end of the period. Change in Unrealized (Gains) Losses for the Period Included in Unrealized Unrealized Earnings for (Gains) / (Gains) / Foreign Liabilities Losses Losses Exchange still held Balance, Realized Included Included in Recognized Transfers Transfers as of Beginning (Gains) / in Credit Risk in OCI or into out of Ending September 30, In millions of Year Losses Earnings in OCI Earnings Purchases Issuances Settlements Sales Level 3 (1) Level 3 (1) Balance 2018 Liabilities: Medium-term notes $ 115 $ (5) $ (1) $ 51 $ (7) $ - $ - $ (30) $ - $ - $ - $ 123 $ (8) Credit derivatives 63 49 (36) - - - - (49) - - - 27 (36) Other derivatives 4 - 3 - - - - - - - - 7 3 Other payable 7 - 2 - - - - (4) - - - 5 2 Liabilities of consolidated VIEs: VIE notes 406 22 (12) (10) 3 - 7 (34) - - - 382 (9) Total liabilities $ 595 $ 66 $ (44) $ 41 $ (4) $ - $ 7 $ (117) $ - $ - $ - $ 544 $ (48) _______________ (1) - Transferred in and out at the end of the period. Change in Unrealized (Gains) Losses for the Period Included in Unrealized Earnings for (Gains) / Unrealized Foreign Liabilities Losses (Gains) / Exchange still held Balance, Realized Included Losses Recognized Transfers Transfers as of Beginning (Gains) / in Included in OCI or into out of Ending September 30, In millions of Year Losses Earnings in OCI Earnings Purchases Issuances Settlements Sales Level 3 (1) Level 3 (1) Balance 2017 Liabilities: Medium-term notes $ 101 $ - $ 13 $ - $ 13 $ - $ - $ - $ - $ - $ - $ 127 $ 26 Credit derivatives 64 41 10 - - - - (41) - - - 74 12 Other derivatives 20 - 18 - - - - (34) - - - 4 18 Other payable - - 1 - - 6 - - - - - 7 1 Liabilities of consolidated VIEs: VIE notes 476 - 56 - - - - (51) (51) - - 430 56 Total liabilities $ 661 $ 41 $ 98 $ - $ 13 $ 6 $ - $ (126) $ (51) $ - $ - $ 642 $ 113 _______________ (1) - Transferred in and out at the end of the period.
Gains And Losses (Realized And Unrealized) Included In Earnings Pertaining To Level 3 Assets And Liabilities	Three Months Ended September 30, 2018 Three Months Ended September 30, 2017 Change in Change in Unrealized Unrealized Gains (Losses) Gains (Losses) for the for the Period Included Period Included in Earnings in Earnings for Assets for Assets and and Total Gains Liabilities still Total Gains Liabilities still (Losses) held as of (Losses) held as of Included September 30, Included September 30, In millions in Earnings 2018 in Earnings 2017 Revenues: Unrealized gains (losses) on insured derivatives $ 4 $ 4 $ 6 $ 6 Realized gains (losses) and other settlements on insured derivatives (6) - (7) - Net gains (losses) on financial instruments at fair value and foreign exchange 4 (1) (4) (4) Other net realized gains (losses) - - (1) (1) Revenues of consolidated VIEs: Net gains (losses) on financial instruments at fair value and foreign exchange 3 14 5 5 Total $ 5 $ 17 $ (1) $ 6 Nine Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Change in Change in Unrealized Unrealized Gains (Losses) Gains (Losses) for the for the Period Included Period Included in Earnings in Earnings for Assets for Assets and and Total Gains Liabilities still Total Gains Liabilities still (Losses) held as of (Losses) held as of Included September 30, Included September 30, In millions in Earnings 2018 in Earnings 2017 Revenues: Unrealized gains (losses) on insured derivatives $ 36 $ 36 $ (10) $ (12) Realized gains (losses) and other settlements on insured derivatives (49) - (41) - Net gains (losses) on financial instruments at fair value and foreign exchange 10 5 (44) (44) Other net realized gains (losses) (2) (2) (1) (1) Revenues of consolidated VIEs: Net gains (losses) on financial instruments at fair value and foreign exchange 28 36 5 5 Total $ 23 $ 75 $ (91) $ (52)
Changes In Fair Value Included In The Company's Consolidated Statements Of Operations	Three Months Ended September 30, Nine Months Ended September 30, In millions 2018 2017 2018 2017 Investments carried at fair value (1) $ 1 $ 2 $ (4) $ 8 Fixed-maturity securities held at fair value-VIE (2) (7) (2) (19) (16) Loans receivable at fair value: Residential mortgage loans (2) (3) (55) (79) (157) Corporate loans (2) - (2) 11 4 Loan repurchase commitments (2) - (1) 9 3 Other assets-VIE (2) 1 - 1 - Medium-term notes (1) 7 (4) 14 (26) Variable interest entity notes (2) 23 70 106 160 Other liabilities (3) - (1) (2) (1) ___________ (1) - Reported within "Net gains (losses) on financial instruments at fair value and foreign exchange" on MBIA's consolidated statements of operations. (2) - Reported within "Net gains (losses) on financial instruments at fair value and foreign exchange-VIE" on MBIA's consolidated statements of operations. (3) - Reported within "Other net realized gains (losses)" on MBIA's consolidated statements of operations.
Difference Between Aggregate Fair Value And The Aggregate Remaining Contractual Principal Balance Outstanding	As of September 30, 2018 As of December 31, 2017 Contractual Contractual Outstanding Fair Outstanding Fair In millions Principal Value Difference Principal Value Difference Loans receivable at fair value: Residential mortgage loans $ 390 $ 389 $ 1 $ 732 $ 727 $ 5 Residential mortgage loans (90 days or more past due) 165 39 126 170 32 138 Corporate loans (90 days or more past due) - - - 1,394 920 474 Total loans receivable at fair value $ 555 $ 428 $ 127 $ 2,296 $ 1,679 $ 617 Variable interest entity notes $ 1,525 $ 709 $ 816 $ 1,882 $ 1,069 $ 813 Medium-term notes $ 139 $ 123 $ 16 $ 180 $ 115 $ 65

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Amortized Cost And Fair Value Of Available-For-Sale And Held-To-Maturity Investment Portfolios	September 30, 2018 Gross Gross Other-Than- Amortized Unrealized Unrealized Fair Temporary In millions Cost Gains Losses Value Impairments (1) AFS Investments Fixed-maturity investments: U.S. Treasury and government agency $ 843 $ 20 $ (19) $ 844 $ - State and municipal bonds 659 111 (14) 756 47 Foreign governments 10 - - 10 - Corporate obligations 1,672 6 (122) 1,556 (68) Mortgage-backed securities: Residential mortgage-backed agency 222 - (7) 215 - Residential mortgage-backed non-agency 32 1 (3) 30 - Commercial mortgage-backed 57 - (2) 55 - Asset-backed securities: Collateralized debt obligations 143 - - 143 - Other asset-backed 214 1 (1) 214 1 Total AFS investments $ 3,852 $ 139 $ (168) $ 3,823 $ (20) HTM Investments Assets of consolidated VIEs: Corporate obligations $ 890 $ 13 $ (2) $ 901 $ - Total HTM investments $ 890 $ 13 $ (2) $ 901 $ - _______________ (1) - Represents unrealized gains or losses on OTTI securities recognized in AOCI, which includes the non-credit component of impairments, as well as all subsequent changes in fair value of such impaired securities reported in AOCI. December 31, 2017 Gross Gross Other-Than- Amortized Unrealized Unrealized Fair Temporary In millions Cost Gains Losses Value Impairments (1) AFS Investments Fixed-maturity investments: U.S. Treasury and government agency $ 1,317 $ 34 $ (6) $ 1,345 $ - State and municipal bonds 840 29 (12) 857 - Foreign governments 10 - - 10 - Corporate obligations 1,332 25 (80) 1,277 (72) Mortgage-backed securities: Residential mortgage-backed agency 365 1 (4) 362 - Residential mortgage-backed non-agency 35 1 (4) 32 - Commercial mortgage-backed 66 - - 66 - Asset-backed securities: Collateralized debt obligations 116 - - 116 - Other asset-backed 175 - - 175 1 Total fixed-maturity investments 4,256 90 (106) 4,240 (71) Money market securities 179 - - 179 - Perpetual debt and equity securities 3 1 - 4 - Total AFS investments $ 4,438 $ 91 $ (106) $ 4,423 $ (71) HTM Investments Assets of consolidated VIEs: Corporate obligations $ 890 $ 26 $ - $ 916 $ - Total HTM investments $ 890 $ 26 $ - $ 916 $ - _______________ (1) - Represents unrealized gains or losses on OTTI securities recognized in AOCI, which includes the non-credit component of impairments, as well as all subsequent changes in fair value of such impaired securities reported in AOCI.
Distribution By Contractual Maturity Of Available-For-Sale and Held-To-Maturity Investments	AFS Securities HTM Securities Consolidated VIEs Amortized Amortized In millions Cost Fair Value Cost Fair Value Due in one year or less $ 790 $ 802 $ - $ - Due after one year through five years 677 702 - - Due after five years through ten years 670 589 - - Due after ten years 1,047 1,073 890 901 Mortgage-backed and asset-backed 668 657 - - Total fixed-maturity investments $ 3,852 $ 3,823 $ 890 $ 901
Gross Unrealized Losses Related To Available-For-Sale And Held-To-Maturity Investments	September 30, 2018 Less than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized In millions Value Losses Value Losses Value Losses AFS Investments Fixed-maturity investments: U.S. Treasury and government agency $ 396 $ (7) $ 206 $ (12) $ 602 $ (19) State and municipal bonds 92 (3) 123 (11) 215 (14) Foreign governments 9 - - - 9 - Corporate obligations 1,116 (38) 213 (84) 1,329 (122) Mortgage-backed securities: Residential mortgage-backed agency 119 (2) 95 (5) 214 (7) Residential mortgage-backed non-agency - - 14 (3) 14 (3) Commercial mortgage-backed 29 - 19 (2) 48 (2) Asset-backed securities: Collateralized debt obligations 73 - - - 73 - Other asset-backed 121 (1) 30 - 151 (1) Total AFS investments $ 1,955 $ (51) $ 700 $ (117) $ 2,655 $ (168) HTM Investments Assets of consolidated VIEs: Corporate obligations $ 313 $ (2) $ - $ - $ 313 $ (2) Total HTM investments $ 313 $ (2) $ - $ - $ 313 $ (2) December 31, 2017 Less than 12 Months 12 Months or Longer Total Fair Unrealized Fair Unrealized Fair Unrealized In millions Value Losses Value Losses Value Losses AFS Investments Fixed-maturity investments: U.S. Treasury and government agency $ 353 $ (1) $ 124 $ (5) $ 477 $ (6) State and municipal bonds 203 (8) 116 (4) 319 (12) Foreign governments 8 - - - 8 - Corporate obligations 425 (3) 163 (77) 588 (80) Mortgage-backed securities: Residential mortgage-backed agency 105 (1) 156 (3) 261 (4) Residential mortgage-backed non-agency - - 14 (4) 14 (4) Commercial mortgage-backed 27 - 5 - 32 - Asset-backed securities: Collateralized debt obligations 12 - - - 12 - Other asset-backed 71 - 39 - 110 - Total AFS investments $ 1,204 $ (13) $ 617 $ (93) $ 1,821 $ (106)
Distribution Of Securities By Percentage Of Fair Value Below Book Value By More Than 5%	AFS Securities Percentage of Fair Value Number of Book Value Fair Value Below Book Value Securities (in millions) (in millions) > 5% to 15% 60 $ 368 $ 338 > 15% to 25% 11 61 50 > 25% to 50% - - - > 50% 4 100 32 Total 75 $ 529 $ 420
Credit Losses Recognized In Earnings Related To OTTI Losses Recognized In Accumulated Other Comprehensive Income (Loss)	In millions Three Months Ended September 30, Nine Months Ended September 30, Credit Losses Recognized in Earnings Related to Other-Than-Temporary Impairments 2018 2017 2018 2017 Beginning balance $ 34 $ 42 $ 32 $ 29 Additions for credit loss impairments recognized in the current period on securities not previously impaired - - - 11 Additions for credit loss impairments recognized in the current period on securities previously impaired 1 2 3 4 Reductions for credit loss impairments previously recognized on securities sold during the period - (2) - (2) Reductions for credit loss impairments previously recognized on securities impaired to fair value during the period - (11) - (11) Ending balance $ 35 $ 31 $ 35 $ 31
Securities Held In Unrealized Loss Position And Insured By Financial Guarantor and The Related Insurance Loss Reserve On Company Insured Investments	Unrealized Insurance Loss In millions Fair Value Loss Reserve (2) Mortgage-backed: MBIA (1) $ 14 $ (3) $ 14 Corporate obligations: MBIA (1) 70 (12) - Other: MBIA (1) 6 - - Other 2 - - Total other 8 - - Total $ 92 $ (15) $ 14 _______________ (1) - Includes investments insured by MBIA Corp. and National. (2) - Insurance loss reserve estimates are based on the proportion of par value owned to the total amount of par value insured.
Gross Realized Gains and Losses From Sales Of Available-For-Sale Securities	Three Months Ended September 30, Nine Months Ended September 30, In millions 2018 2017 2018 2017 Proceeds from sales $ 583 $ 312 $ 1,647 $ 1,300 Gross realized gains $ 1 $ 5 $ 4 $ 24 Gross realized losses $ (2) $ (5) $ (15) $ (9)
Portion Of Unrealized Gains Losses Recognized On Equity Investments [Table Text Block]	In millions Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 Net gains (losses) recognized during the period on equity securities $ 3 $ 3 Less: Net gains (losses) recognized during the period on equity securities sold during the period - 1 Unrealized gains (losses) recognized during the period on equity securities still held as of September 30, 2018 $ 3 $ 2

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Credit Derivatives Sold	$ in millions As of September 30, 2018 Notional Value Credit Derivatives Sold Weighted Average Remaining Expected Maturity AAA AA A BBB Below Investment Grade Total Notional Fair Value Asset (Liability) Insured credit default swaps 0.3 Years $ - $ - $ - $ - $ 77 $ 77 $ (27) Insured swaps 15.5 Years - 107 1,539 915 - 2,561 (2) Total notional $ - $ 107 $ 1,539 $ 915 $ 77 $ 2,638 Total fair value $ - $ - $ (1) $ (1) $ (27) $ (29) $ in millions As of December 31, 2017 Notional Value Credit Derivatives Sold Weighted Average Remaining Expected Maturity AAA AA A BBB Below Investment Grade Total Notional Fair Value Asset (Liability) Insured credit default swaps 1.0 Years $ - $ - $ - $ - $ 127 $ 127 $ (63) Insured swaps 15.5 Years - 117 1,818 846 20 2,801 (2) Total notional $ - $ 117 $ 1,818 $ 846 $ 147 $ 2,928 Total fair value $ - $ - $ (1) $ (1) $ (63) $ (65)
Total Fair Value Of Company's Derivative Assets And Liabilities By Instrument And Balance Sheet Location, Before Counterparty Netting	In millions Derivative Assets (1) Derivative Liabilities (1) Notional Amount Fair Fair Derivative Instruments Outstanding Balance Sheet Location Value Balance Sheet Location Value Not designated as hedging instruments: Insured credit default swaps $ 77 Other assets $ - Derivative liabilities $ (27) Insured swaps 2,561 Other assets - Derivative liabilities (2) Interest rate swaps 722 Other assets 2 Derivative liabilities (136) Interest rate swaps-embedded 296 Medium-term notes - Medium-term notes (10) Currency swaps-VIE 64 Other assets-VIE 14 Derivative liabilities-VIE - All other 49 Other assets - Derivative liabilities (8) Total non-designated derivatives $ 3,769 $ 16 $ (183) __________ (1) - In accordance with the accounting guidance for derivative instruments and hedging activities, the balance sheet location of the Company’s embedded derivative instruments is determined by the location of the related host contract. In millions Derivative Assets (1) Derivative Liabilities (1) Notional Amount Fair Fair Derivative Instruments Outstanding Balance Sheet Location Value Balance Sheet Location Value Not designated as hedging instruments: Insured credit default swaps $ 127 Other assets $ - Derivative liabilities $ (63) Insured swaps 2,801 Other assets - Derivative liabilities (2) Interest rate swaps 747 Other assets 2 Derivative liabilities (193) Interest rate swaps-embedded 305 Medium-term notes 1 Medium-term notes (6) Currency swaps-VIE 69 Other assets-VIE 19 Derivative liabilities-VIE - All other 49 Other assets - Derivative liabilities (4) All other-embedded 2 Other investments - Other investments (1) Total non-designated derivatives $ 4,100 $ 22 $ (269) __________ (1) - In accordance with the accounting guidance for derivative instruments and hedging activities, the balance sheet location of the Company’s embedded derivative instruments is determined by the location of the related host contract.
Effect Of Derivative Instruments On Consolidated Statements Of Operations	In millions Derivatives Not Designated as Three Months Ended September 30, Hedging Instruments Location of Gain (Loss) Recognized in Income on Derivative 2018 2017 Insured credit default swaps Unrealized gains (losses) on insured derivatives $ 4 $ 6 Insured credit default swaps Realized gains (losses) and other settlements on insured derivatives (5) (7) Interest rate swaps Net gains (losses) on financial instruments at fair value and foreign exchange 7 (3) Currency swaps-VIE Net gains (losses) on financial instruments at fair value and foreign exchange-VIE - 4 All other Net gains (losses) on financial instruments at fair value and foreign exchange (4) - Total $ 2 $ - In millions Derivatives Not Designated as Nine Months Ended September 30, Hedging Instruments Location of Gain (Loss) Recognized in Income on Derivative 2018 2017 Insured credit default swaps Unrealized gains (losses) on insured derivatives $ 36 $ (10) Insured credit default swaps Realized gains (losses) and other settlements on insured derivatives (49) (41) Interest rate swaps Net gains (losses) on financial instruments at fair value and foreign exchange 33 (8) Currency swaps-VIE Net gains (losses) on financial instruments at fair value and foreign exchange-VIE (5) (6) All other Net gains (losses) on financial instruments at fair value and foreign exchange (4) (19) Total $ 11 $ (84)

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Income tax rate reconciliation from statutory to effective tax rate	Three Months Ended September 30, Nine Months Ended September 30, In millions 2018 2017 2018 2017 Income (loss) before income taxes $ (45) $ (273) $ (287) $ (603) Provision (benefit) for income taxes $ - $ (6) $ 2 $ 965 Effective tax rate -% 2.2% -0.7% -160.0%

Business Segments (Tables)

Business Segments (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Summary of company's segment results	Three Months Ended September 30, 2018 U.S. International Public and Structured Finance Finance In millions Insurance Corporate Insurance Eliminations Consolidated Revenues (1) $ 45 $ 7 $ 58 $ - $ 110 Net change in fair value of insured derivatives - - (1) - (1) Net gains (losses) on financial instruments at fair value and foreign exchange 1 17 (13) - 5 Net investment losses related to other-than-temporary impairments (1) - - - (1) Net gains (losses) on extinguishment of debt - 3 - - 3 Other net realized gains (losses) - - 1 - 1 Revenues of consolidated VIEs - - (12) - (12) Inter-segment revenues (2) 7 11 6 (24) - Total revenues 52 38 39 (24) 105 Losses and loss adjustment 48 - (2) - 46 Operating 5 13 9 - 27 Interest - 20 32 - 52 Expenses of consolidated VIEs - - 25 - 25 Inter-segment expenses (2) 10 5 9 (24) - Total expenses 63 38 73 (24) 150 Income (loss) before income taxes (11) - (34) - (45) Provision (benefit) for income taxes (3) 2 - 1 - Net income (loss) $ (8) $ (2) $ (34) $ (1) $ (45) Identifiable assets $ 4,453 $ 1,062 $ 5,026 $ (2,180) (3) $ 8,361 ________________ (1) - Represents the sum of third-party financial guarantee net premiums earned, net investment income, insurance-related fees and reimbursements and other fees. (2) - Represents intercompany premium income and expense and intercompany interest income and expense pertaining to intercompany receivables and payables. (3) - Consists primarily of intercompany reinsurance balances and repurchase agreements. Three Months Ended September 30, 2017 U.S. International Public and Structured Finance Finance In millions Insurance Corporate Insurance Eliminations Consolidated Revenues (1) $ 70 $ 7 $ 10 $ - $ 87 Net change in fair value of insured derivatives - - (1) - (1) Net gains (losses) on financial instruments at fair value and foreign exchange 2 (15) 2 - (11) Net investment losses related to other-than-temporary impairments (71) - - - (71) Net gains (losses) on extinguishment of debt - 1 - - 1 Other net realized gains (losses) (1) (1) 1 - (1) Revenues of consolidated VIEs - - 29 - 29 Inter-segment revenues (2) 4 15 11 (30) - Total revenues 4 7 52 (30) 33 Losses and loss adjustment 141 - 64 - 205 Operating 8 14 7 - 29 Interest - 22 28 - 50 Expenses of consolidated VIEs - - 22 - 22 Inter-segment expenses (2) 16 - 14 (30) - Total expenses 165 36 135 (30) 306 Income (loss) before income taxes (161) (29) (83) - (273) Provision (benefit) for income taxes (55) (1) 1 49 (6) Net income (loss) $ (106) $ (28) $ (84) $ (49) $ (267) Identifiable assets $ 5,051 $ 1,205 $ 5,320 $ (2,032) (3) $ 9,544 ________________ (1) - Represents the sum of third-party financial guarantee net premiums earned, net investment income, insurance-related fees and reimbursements and other fees. (2) - Represents intercompany premium income and expense and intercompany interest income and expense pertaining to intercompany receivables and payables. (3) - Consists primarily of intercompany reinsurance balances and repurchase agreements. Nine Months Ended September 30, 2018 U.S. International Public and Structured Finance Finance In millions Insurance Corporate Insurance Eliminations Consolidated Revenues (1) $ 139 $ 20 $ 98 $ - $ 257 Net change in fair value of insured derivatives - - (13) - (13) Net gains (losses) on financial instruments at fair value and foreign exchange (13) 48 (17) - 18 Net investment losses related to other-than-temporary impairments (3) - - - (3) Net gains (losses) on extinguishment of debt - 3 - - 3 Other net realized gains (losses) - (2) 2 - - Revenues of consolidated VIEs - - (72) - (72) Inter-segment revenues (2) 20 36 18 (74) - Total revenues 143 105 16 (74) 190 Losses and loss adjustment 184 - (7) - 177 Operating 14 39 21 - 74 Interest - 60 95 - 155 Expenses of consolidated VIEs - - 71 - 71 Inter-segment expenses (2) 34 14 27 (75) - Total expenses 232 113 207 (75) 477 Income (loss) before income taxes (89) (8) (191) 1 (287) Provision (benefit) for income taxes (20) (31) (5) 58 2 Net income (loss) $ (69) $ 23 $ (186) $ (57) $ (289) Identifiable assets $ 4,453 $ 1,062 $ 5,026 $ (2,180) (3) $ 8,361 ________________ (1) - Represents the sum of third-party financial guarantee net premiums earned, net investment income, insurance-related fees and reimbursements and other fees. (2) - Represents intercompany premium income and expense and intercompany interest income and expense pertaining to intercompany receivables and payables. (3) - Consists primarily of intercompany reinsurance balances and repurchase agreements. Nine Months Ended September 30, 2017 U.S. International Public and Structured Finance Finance In millions Insurance Corporate Insurance Eliminations Consolidated Revenues (1) $ 200 $ 23 $ 54 $ - $ 277 Net change in fair value of insured derivatives - - (51) - (51) Net gains (losses) on financial instruments at fair value and foreign exchange 20 (54) (21) - (55) Net investment losses related to other-than-temporary impairments (84) - - - (84) Net gains (losses) on extinguishment of debt - 9 - - 9 Other net realized gains (losses) (1) (3) 40 - 36 Revenues of consolidated VIEs - - 50 - 50 Inter-segment revenues (2) 14 46 31 (91) - Total revenues 149 21 103 (91) 182 Losses and loss adjustment 310 - 159 - 469 Operating 34 46 25 - 105 Interest - 66 82 - 148 Expenses of consolidated VIEs - - 63 - 63 Inter-segment expenses (2) 47 2 42 (91) - Total expenses 391 114 371 (91) 785 Income (loss) before income taxes (242) (93) (268) - (603) Provision (benefit) for income taxes (86) 1,069 1,143 (1,161) 965 Net income (loss) $ (156) $ (1,162) $ (1,411) $ 1,161 $ (1,568) Identifiable assets $ 5,051 $ 1,205 $ 5,320 $ (2,032) (3) $ 9,544 ________________ (1) - Represents the sum of third-party financial guarantee net premiums earned, net investment income, insurance-related fees and reimbursements and other fees. (2) - Represents intercompany premium income and expense and intercompany interest income and expense pertaining to intercompany receivables and payables. (3) - Consists primarily of intercompany reinsurance balances and repurchase agreements.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Schedule Of Basic And Diluted Earnings Per Share	Three Months Ended September 30, Nine Months Ended September 30, In millions except per share amounts 2018 2017 2018 2017 Basic earnings per share: Net income (loss) available to common shareholders $ (45) $ (267) $ (289) $ (1,568) Basic weighted average shares (1) 89.5 123.0 89.1 126.6 Net income (loss) per basic common share $ (0.50) $ (2.17) $ (3.24) $ (12.38) Diluted earnings per share: Net income (loss) available to common shareholders $ (45) $ (267) $ (289) $ (1,568) Diluted weighted average shares 89.5 123.0 89.1 126.6 Net income (loss) per diluted common share $ (0.50) $ (2.17) $ (3.24) $ (12.38) Potentially dilutive securities excluded from the calculation of diluted EPS because of antidilutive affect (2) 1.4 14.4 1.4 14.4 _________ (1) - Includes 0.9 million and 0.3 million of participating securities that met the service condition and were eligible to receive nonforfeitable dividends or dividend equivalents for the three months ended September 30, 2018 and 2017, respectively. Includes 0.8 million and 0.3 of participating securities that met the service condition and were eligible to receive nonforfeitable dividends or dividend equivalents for the nine months ended September 30, 2018 and 2017, respectively. (2) - Includes securities that if exercised or vested would be net share settled resulting in a significantly lower impact to the outstanding share balance.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2018
Text Block [Abstract]
Changes In The Components Of AOCI	Unrealized Instrument-Specific Gains (Losses) Credit Risk of on AFS Foreign Currency Liabilities Measured In millions Securities, Net Translation, Net at Fair Value, Net Total Balance, December 31, 2017 $ (10) $ (9) $ - $ (19) ASU 2016-01 transition adjustment (2) - (162) (164) ASU 2018-02 transition adjustment (3) - - (3) Net period other comprehensive income (loss) (18) 2 (4) (20) Balance, September 30, 2018 $ (33) $ (7) $ (166) $ (206)
Reclassifications From AOCI	In millions Amounts Reclassified from AOCI Three Months Ended September 30, Nine Months Ended September 30, Details about AOCI Components 2018 2017 2018 2017 Affected Line Item on the Consolidated Statements of Operations Unrealized gains (losses) on AFS securities: Realized gains (losses) on sale of securities $ 2 $ - $ 4 $ 6 Net gains (losses) on financial instruments at fair value and foreign exchange OTTI (2) (4) (3) (6) Net investment losses related to OTTI Amortization on securities - (1) (1) (2) Net investment income - (5) - (2) Income (loss) before income taxes - - - (1) Provision (benefit) for income taxes Total reclassifications for the period $ - $ (5) $ - $ (1) Net income (loss)

Business Developments And Ris_2

Business Developments And Risks And Uncertainties (Narrative) (Detail) $ / shares in Units, $ in Millions	Nov. 02, 2018USD ($)	Oct. 11, 2018USD ($)	Sep. 30, 2018USD ($)segments$ / sharesshares
Business Acquisition [Line Items]
Number of operating segments | segments			3
Warrants outstanding | shares			11,850,000
Warrant exercise price | $ / shares			$ 9.59
Treasury shares issued (in shares) | shares			1,300,000
Zohar [Member]
Business Acquisition [Line Items]
Aggregate claim amount			$ 919
Puerto Rico [Member]
Business Acquisition [Line Items]
Claims payments			$ 276
SubsequentEvent [Member]
Business Acquisition [Line Items]
Increase in MBIA Inc's liquidity	$ 41
National [Member] | SubsequentEvent [Member]
Business Acquisition [Line Items]
Dividends from subsidiaries		$ 108
MBIA Inc. Senior Notes [Member] | SubsequentEvent [Member]
Business Acquisition [Line Items]
Long-term debt, interest rate	5.70%
Long-term debt, maturity year	2,034
Mbia Inc. Debentures [Member] | SubsequentEvent [Member]
Business Acquisition [Line Items]
Long-term debt, interest rate	7.00%
Long-term debt, maturity year	2,025

Significant Accounting Polici_3

Significant Accounting Policies (Narrative) (Detail) $ in Millions	3 Months Ended
	Sep. 30, 2018USD ($)
Accounting Policy [Line Items]
Out of Period Adjustment	$ 6
Second Quarter 2018 Reporting Period [Member]
Accounting Policy [Line Items]
Out of Period Adjustment	3
First Quarter 2017 Reporting Period [Member]
Accounting Policy [Line Items]
Out of Period Adjustment	$ 3

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Narrative) (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)
ASU 2016-01 [Member] | Financial Liabilities [Member]
Cumulative effect of prospective application of new accounting principle	$ 162
ASU 2016-01 [Member] | Equity Investments [Member]
Cumulative effect of prospective application of new accounting principle	2
ASU 2018-02 [Member]
Cumulative effect of prospective application of new accounting principle	$ 3

Variable Interest Entities (Nar

Variable Interest Entities (Narrative) (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Variable Interest Entity [Line Items]
Carrying amounts of assets	$ 1,900		$ 1,900	$ 3,200
Carrying amounts of liabilities	$ 2,000		$ 2,000	$ 2,300
Variable Interest Entity Primary Beneficiary [Member] | Structured Finance And International Insurance [Member]
Variable Interest Entity [Line Items]
Number of variable interest entities consolidated			0
Number of variable interest entities deconsolidated	3
Variable Interest Entity Primary Beneficiary [Member] | Structured Finance And International Insurance [Member] | Zohar Funds Bankruptcy Cases Debtors [Member]
Variable Interest Entity [Line Items]
Net realized gains (losses) related to deconsolidation		$ (93)
Number of variable interest entities deconsolidated		2

Variable Interest Entities (Sum

Variable Interest Entities (Summary Of Nonconsolidated VIEs Assets And Liabilities) (Detail) - USD ($) $ in Millions		Sep. 30, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
VIE Assets		$ 29,436	$ 30,507
Maximum Exposure to Loss		7,569	8,985
Investments [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[1]	18	19
Premiums Receivable [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[2]	40	49
Insurance Loss Recoverable [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[3]	983	173
Unearned Premium Revenue [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Liabilities	[4]	42	51
Loss And Loss Adjustment Expense Reserves [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Liabilities	[5]	376	406
Global Structured Finance [Member]
Variable Interest Entity [Line Items]
VIE Assets		14,378	14,939
Maximum Exposure to Loss		5,273	6,461
Global Structured Finance [Member] | Investments [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[1]	18	19
Global Structured Finance [Member] | Premiums Receivable [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[2]	31	39
Global Structured Finance [Member] | Insurance Loss Recoverable [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[3]	983	173
Global Structured Finance [Member] | Unearned Premium Revenue [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Liabilities	[4]	30	37
Global Structured Finance [Member] | Loss And Loss Adjustment Expense Reserves [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Liabilities	[5]	376	406
Global Structured Finance [Member] | Residential Mortgage Backed Securities [Member]
Variable Interest Entity [Line Items]
VIE Assets		5,879	7,295
Maximum Exposure to Loss		3,251	3,741
Global Structured Finance [Member] | Residential Mortgage Backed Securities [Member] | Investments [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[1]	18	19
Global Structured Finance [Member] | Residential Mortgage Backed Securities [Member] | Premiums Receivable [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[2]	20	22
Global Structured Finance [Member] | Residential Mortgage Backed Securities [Member] | Insurance Loss Recoverable [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[3]	143	172
Global Structured Finance [Member] | Residential Mortgage Backed Securities [Member] | Unearned Premium Revenue [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Liabilities	[4]	18	20
Global Structured Finance [Member] | Residential Mortgage Backed Securities [Member] | Loss And Loss Adjustment Expense Reserves [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Liabilities	[5]	356	396
Global Structured Finance [Member] | Commercial Mortgage Backed Securities [Member]
Variable Interest Entity [Line Items]
VIE Assets		131	216
Maximum Exposure to Loss		59	94
Global Structured Finance [Member] | Commercial Mortgage Backed Securities [Member] | Investments [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[1]	0	0
Global Structured Finance [Member] | Commercial Mortgage Backed Securities [Member] | Premiums Receivable [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[2]	0	0
Global Structured Finance [Member] | Commercial Mortgage Backed Securities [Member] | Insurance Loss Recoverable [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[3]	0	0
Global Structured Finance [Member] | Commercial Mortgage Backed Securities [Member] | Unearned Premium Revenue [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Liabilities	[4]	0	0
Global Structured Finance [Member] | Commercial Mortgage Backed Securities [Member] | Loss And Loss Adjustment Expense Reserves [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Liabilities	[5]	0	0
Global Structured Finance [Member] | Consumer Asset Backed [Member]
Variable Interest Entity [Line Items]
VIE Assets		4,514	5,010
Maximum Exposure to Loss		586	981
Global Structured Finance [Member] | Consumer Asset Backed [Member] | Investments [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[1]	0	0
Global Structured Finance [Member] | Consumer Asset Backed [Member] | Premiums Receivable [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[2]	2	4
Global Structured Finance [Member] | Consumer Asset Backed [Member] | Insurance Loss Recoverable [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[3]	1	1
Global Structured Finance [Member] | Consumer Asset Backed [Member] | Unearned Premium Revenue [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Liabilities	[4]	1	3
Global Structured Finance [Member] | Consumer Asset Backed [Member] | Loss And Loss Adjustment Expense Reserves [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Liabilities	[5]	10	10
Global Structured Finance [Member] | Corporate Asset Backed [Member]
Variable Interest Entity [Line Items]
VIE Assets		3,854	2,418
Maximum Exposure to Loss		1,377	1,645
Global Structured Finance [Member] | Corporate Asset Backed [Member] | Investments [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[1]	0	0
Global Structured Finance [Member] | Corporate Asset Backed [Member] | Premiums Receivable [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[2]	9	13
Global Structured Finance [Member] | Corporate Asset Backed [Member] | Insurance Loss Recoverable [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[3]	839	0
Global Structured Finance [Member] | Corporate Asset Backed [Member] | Unearned Premium Revenue [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Liabilities	[4]	11	14
Global Structured Finance [Member] | Corporate Asset Backed [Member] | Loss And Loss Adjustment Expense Reserves [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Liabilities	[5]	10	0
Global Public Finance [Member]
Variable Interest Entity [Line Items]
VIE Assets		15,058	15,568
Maximum Exposure to Loss		2,296	2,524
Global Public Finance [Member] | Investments [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[1]	0	0
Global Public Finance [Member] | Premiums Receivable [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[2]	9	10
Global Public Finance [Member] | Insurance Loss Recoverable [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Assets	[3]	0	0
Global Public Finance [Member] | Unearned Premium Revenue [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Liabilities	[4]	12	14
Global Public Finance [Member] | Loss And Loss Adjustment Expense Reserves [Member]
Variable Interest Entity [Line Items]
Carrying Value of VIE Liabilities	[5]	$ 0	$ 0
[1]	Reported within Investments on MBIA's consolidated balance sheets.
[2]	Reported within Premiums receivable on MBIA's consolidated balance sheets.
[3]	Reported within Insurance loss recoverable on MBIA's consolidated balance sheets.
[4]	Reported within Unearned premium revenue on MBIA's consolidated balance sheets.
[5]	Reported within Loss and loss adjustment expense reserves on MBIA's consolidated balance sheets.

Loss And Loss Adjustment Expe_3

Loss And Loss Adjustment Expense Reserves (Loss And LAE Activity) (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Loss And Loss Adjustment Expense Reserves [Line Items]
Weighted average risk-free rate used to discount claim liability			3.03%
Losses and loss adjustment	$ 46	$ 205	$ 177	$ 469
Lae [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Loss and loss adjustment expense reserves	74		74		$ 66
Losses and loss adjustment	$ 6	$ 6	$ 28	$ 33

Loss And Loss Adjustment Expe_4

Loss And Loss Adjustment Expense Reserves (Schedule OF Losses And Loss Adjustment Expenses Reserves and Recoveries) (Detail) - USD ($) $ in Millions		Sep. 30, 2018	Dec. 31, 2017
Loss And Lae Reserves [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Loss and loss adjustment expense reserves		$ 1,033	$ 979
Insurance Loss Recoverable [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Insurance Loss Recoverable		1,542	511
U S Public Finance Insurance [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Insurance Loss Recoverable		554	333
Loss and loss adjustment expense reserves		634	512
International And Structured Finance Insurance [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Insurance Loss Recoverable	[1]	1,457	1,478
Loss and loss adjustment expense reserves	[1]	628	710
International And Structured Finance Insurance [Member] | Variable Interest Entity Primary Beneficiary [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Insurance Loss Recoverable	[1]	(469)	(1,300)
Loss and loss adjustment expense reserves	[1]	(229)	(243)
International And Structured Finance Insurance [Member] | Variable Interest Entity Primary Beneficiary [Member] | Loan Repurchase Commitments [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Loan repurchase commitments		415	407
International And Structured Finance Insurance [Member] | Non Variable Interest Entity [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Insurance Loss Recoverable		988	178
Loss and loss adjustment expense reserves		$ 399	$ 467
[1]	Includes loan repurchase commitments of $415 million and $407 million as of September 30, 2018 and December 31, 2017, respectively.

Loss And Loss Adjustment Expe_5

Loss And Loss Adjustment Expense Reserves (Schedule Of Loss And Loss Adjustment Expenses Reserves) (Detail) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017
Loss And Loss Adjustment Expense Reserves [Line Items]
Changes in unearned premium revenue		$ 142	$ 149
Loss And Lae Reserves [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Gross loss and LAE reserve, beginning balance		979
Loss payments for cases		(344)
Accretion of claim liability discount		18
Changes in discount rates		25
Changes in assumptions		336
Changes in unearned premium revenue		12
Changes in LAE		8
Other	[1]	(1)
Gross loss and LAE reserve, ending balance		$ 1,033
[1]	Primarily changes in amount and timing of collections.

Loss And Loss Adjustment Expe_6

Loss And Loss Adjustment Expense Reserves (Schedule Of Insurance Loss Recoverable And Changes In Recoveries On Unpaid Losses) (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)
Loss And Loss Adjustment Expense Recoveries [Line Items]
Gross Reserve beginning balance, Total	$ 546
Collections for Cases	(42)
Accretion of Recoveries	15
Changes in Discount Rates	(30)
Changes in Assumptions	1,076
Changes in LAE Recoveries	(6)
Other	4	[1]
Gross Reserve ending balance, Total	1,563
Insurance Loss Recoverable [Member]
Loss And Loss Adjustment Expense Recoveries [Line Items]
Gross Reserve beginning balance, Insurance loss recoverable	511
Collections for Cases	(42)
Accretion of Recoveries	14
Changes in Discount Rates	(29)
Changes in Assumptions	1,084	[2]
Changes in LAE Recoveries	0
Other	4	[1]
Gross Reserve ending balance, Insurance loss recoverable	1,542
Recoveries On Unpaid Losses [Member]
Loss And Loss Adjustment Expense Recoveries [Line Items]
Gross Reserve beginning balance,Recoveries on unpaid losses	35	[3]
Collections for Cases	0
Accretion of Recoveries	1	[3]
Changes in Discount Rates	(1)	[3]
Changes in Assumptions	(8)	[3]
Changes in LAE Recoveries	(6)	[3]
Other	0
Gross Reserve ending balance, Recoveries on unpaid losses	$ 21	[3]
[1]	Primarily changes in amount and timing of collections.
[2]	Includes amounts which have been paid and are expected to be recovered in the future.
[3]	As of September 30, 2018 and December 31, 2017, excludes Puerto Rico recoveries, which have been netted against reserves.

Loss And Loss Adjustment Expe_7

Loss And Loss Adjustment Expense Reserves (Schedule Of Financial Guarantees And Related Claim Liability) (Detail) $ in Millions		9 Months Ended	12 Months Ended
		Sep. 30, 2018USD ($)issuepolicy	Dec. 31, 2017USD ($)issuepolicy
Loss And Loss Adjustment Expense Reserves [Line Items]
Number of policies | policy		319	375
Number of issues | issue	[1]	131	144
Remaining weighted average contract period (in years)		9 years	8 years 10 months 24 days
Principal	[2]	$ 7,660	$ 8,964
Interest	[2]	7,888	8,481
Total	[2]	15,548	17,445
Gross claim liability	[3]	1,076	1,082
Less: Gross potential recoveries	[4]	2,058	782
Discount, net	[5]	(483)	(178)
Net claim liability (recoverable)		(499)	478
Unearned premium revenue		75	90
Reinsurance recoverables on paid and unpaid losses	[6]	$ 23	$ 17
Caution List Low [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Number of policies | policy		56	89
Number of issues | issue	[1]	16	20
Remaining weighted average contract period (in years)		7 years 2 months 12 days	7 years 4 months 24 days
Principal	[2]	$ 1,933	$ 2,764
Interest	[2]	2,314	2,676
Total	[2]	4,247	5,440
Gross claim liability	[3]	0	0
Less: Gross potential recoveries		0	0
Discount, net	[5]	0	0
Net claim liability (recoverable)		0	0
Unearned premium revenue		$ 6	$ 9
Caution List Medium [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Number of policies | policy		20	5
Number of issues | issue	[1]	6	4
Remaining weighted average contract period (in years)		8 years	4 years 3 months 18 days
Principal	[2]	$ 262	$ 13
Interest	[2]	131	3
Total	[2]	393	16
Gross claim liability	[3]	0	0
Less: Gross potential recoveries		0	0
Discount, net	[5]	0	0
Net claim liability (recoverable)		0	0
Unearned premium revenue		$ 4	$ 0
Caution List High [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Number of policies | policy		0	1
Number of issues | issue	[1]	0	1
Remaining weighted average contract period (in years)			8 years 8 months 12 days
Principal	[2]	$ 0	$ 104
Interest	[2]	0	46
Total	[2]	0	150
Gross claim liability	[3]	0	0
Less: Gross potential recoveries		0	0
Discount, net	[5]	0	0
Net claim liability (recoverable)		0	0
Unearned premium revenue		$ 0	$ 4
Classified List [Member]
Loss And Loss Adjustment Expense Reserves [Line Items]
Number of policies | policy		243	280
Number of issues | issue	[1]	109	119
Remaining weighted average contract period (in years)		9 years 8 months 12 days	9 years 8 months 12 days
Principal	[2]	$ 5,465	$ 6,083
Interest	[2]	5,443	5,756
Total	[2]	10,908	11,839
Gross claim liability	[3]	1,076	1,082
Less: Gross potential recoveries	[4]	2,058	782
Discount, net	[5]	(483)	(178)
Net claim liability (recoverable)		(499)	478
Unearned premium revenue		$ 65	$ 77
[1]	An “issue” represents the aggregate of financial guarantee policies that share the same revenue source for purposes of making debt service payments on the insured debt.
[2]	Represents contractual principal and interest payments due by the issuer of the obligations insured by MBIA.
[3]	The gross claim liability with respect to Puerto Rico exposures are net of expected recoveries for policies in a net payable position.
[4]	Gross potential recoveries with respect to certain Puerto Rico exposures are net of the claim liability for policies in a net recoverable position.
[5]	Represents discount related to Gross Claim Liability and Gross Potential Recoveries.
[6]	Included in "Other assets" on the Company's consolidated balance sheet.

Fair Value Of Financial Instr_3

Fair Value Of Financial Instruments (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Percentage of level 3 assets at fair value in total assets measured at fair value value	16.00%	16.00%	30.00%
Percentage of level 3 liabilities at fair value in total liabilities measured at fair value	54.00%	54.00%	41.00%
Cumulative changes in instrument-specific credit risk of liabilities elected under the fair value option	$ (206)	$ (206)	$ (19)
Instrument-specific credit risk of liabilities measured at fair value, net [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cumulative changes in instrument-specific credit risk of liabilities elected under the fair value option	(166)	(166)	$ 0
Loss on instrument-specific credit risk recognized in earnings	$ 38	$ 48

Fair Value Of Financial Instr_4

Fair Value Of Financial Instruments (Quantitative Information Regarding The Significant Unobservable Inputs For Certain Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Detail) - USD ($) $ in Millions		Sep. 30, 2018	Dec. 31, 2017
Cash Flows [Member] | Other Derivative Liabilities [Member] | Discounted cash flow [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value, liabilities		$ 7	$ 4
Cash Flows [Member] | Other Derivative Liabilities [Member] | Minimum [Member] | Discounted cash flow [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Range dollars		0	0
Cash Flows [Member] | Other Derivative Liabilities [Member] | Maximum [Member] | Discounted cash flow [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Range dollars		49	49
Cash Flows [Member] | Other Derivative Liabilities [Member] | Weighted Average [Member] | Discounted cash flow [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Range dollars	[1]	25	25
Credit Derivatives [Member] | Nonperformance Risk [Member] | Commercial Mortgage Backed Securities [Member] | Direct Price Model [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value, liabilities		$ 27	$ 63
Credit Derivatives [Member] | Nonperformance Risk [Member] | Commercial Mortgage Backed Securities [Member] | Minimum [Member] | Direct Price Model [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Range percentage		54.00%	54.00%
Credit Derivatives [Member] | Nonperformance Risk [Member] | Commercial Mortgage Backed Securities [Member] | Maximum [Member] | Direct Price Model [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Range percentage		54.00%	54.00%
Credit Derivatives [Member] | Nonperformance Risk [Member] | Commercial Mortgage Backed Securities [Member] | Weighted Average [Member] | Direct Price Model [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Range percentage		54.00%	54.00%
Loans Receivable [Member] | Variable Interest Entity Primary Beneficiary [Member] | Impact Of Financial Guarantee [Member] | Quoted market prices adjusted for financial guarantees provided to VIE obligations and multiples of EBITDA [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value, assets		$ 428	$ 1,679
Loans Receivable [Member] | Variable Interest Entity Primary Beneficiary [Member] | Impact Of Financial Guarantee [Member] | Minimum [Member] | Quoted market prices adjusted for financial guarantees provided to VIE obligations and multiples of EBITDA [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Range percentage		(18.00%)	(25.00%)
Loans Receivable [Member] | Variable Interest Entity Primary Beneficiary [Member] | Impact Of Financial Guarantee [Member] | Maximum [Member] | Quoted market prices adjusted for financial guarantees provided to VIE obligations and multiples of EBITDA [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Range percentage		63.00%	35.00%
Loans Receivable [Member] | Variable Interest Entity Primary Beneficiary [Member] | Impact Of Financial Guarantee [Member] | Weighted Average [Member] | Quoted market prices adjusted for financial guarantees provided to VIE obligations and multiples of EBITDA [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Range percentage		(5.00%)	(2.00%)
Loan Repurchase Commitments [Member] | Variable Interest Entity Primary Beneficiary [Member] | Recovery Rates And Breach Rates [Member] | Discounted cash flow [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair Value, assets		$ 415	$ 407
Variable Interest Entity Notes [Member] | Variable Interest Entity Primary Beneficiary [Member] | Impact Of Financial Guarantee [Member] | Quoted market prices of VIE assets adjusted for financial guarantees provided [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value, liabilities		$ 382	$ 406
Variable Interest Entity Notes [Member] | Variable Interest Entity Primary Beneficiary [Member] | Impact Of Financial Guarantee [Member] | Minimum [Member] | Quoted market prices of VIE assets adjusted for financial guarantees provided [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Range percentage		0.00%	0.00%
Variable Interest Entity Notes [Member] | Variable Interest Entity Primary Beneficiary [Member] | Impact Of Financial Guarantee [Member] | Maximum [Member] | Quoted market prices of VIE assets adjusted for financial guarantees provided [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Range percentage		65.00%	60.00%
Variable Interest Entity Notes [Member] | Variable Interest Entity Primary Beneficiary [Member] | Impact Of Financial Guarantee [Member] | Weighted Average [Member] | Quoted market prices of VIE assets adjusted for financial guarantees provided [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Range percentage		40.00%	36.00%
[1]	Midpoint of cash flows are used for the weighted average.

Fair Value Of Financial Instr_5

Fair Value Of Financial Instruments (Company's Assets And Liabilities Measured At Fair Value On Recurring Basis) (Detail) - USD ($) $ in Millions		Sep. 30, 2018	Dec. 31, 2017
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		$ 5,421	$ 7,102
Fair value financial liabilities measured on recurring basis		1,010	1,459
Money Market Securities [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		147	180
Medium Term Notes [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis		123	115
Perpetual Debt And Equity Securities [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		64	63
Cash And Cash Equivalents [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		167	122
Fixed Income Funds [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis	[1]	75	82
Fixed Maturities [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		3,919	4,328
Fixed Maturities [Member] | U S Treasury And Government [Member] | Other Fixed Maturity Investments [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		854	1,352
Fixed Maturities [Member] | State and municipal bonds [Member] | Other Fixed Maturity Investments [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		757	858
Fixed Maturities [Member] | Foreign Government Debt [Member] | Other Fixed Maturity Investments [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		11	10
Fixed Maturities [Member] | Corporate Obligations [Member] | Other Fixed Maturity Investments [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		1,623	1,340
Fixed Maturities [Member] | Residential Mortgage Backed Agency [Member] | Mortgage-backed [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		220	368
Fixed Maturities [Member] | Residential Mortgage Backed Non Agency [Member] | Mortgage-backed [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		30	32
Fixed Maturities [Member] | Commercial Mortgage Backed Securities [Member] | Mortgage-backed [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		57	67
Fixed Maturities [Member] | Collateralized Debt Obligations [Member] | Asset-backed [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		146	118
Fixed Maturities [Member] | Other Asset Backed [Member] | Asset-backed [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		221	183
Derivative Assets [Member] | Interest Rate Derivatives [Member] | Non Insured Derivatives [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		2	2
Assets Of Consolidated V I Es [Member] | Variable Interest Entity Primary Beneficiary [Member] | Loan Repurchase Commitments [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		415	407
Assets Of Consolidated V I Es [Member] | Corporate Obligations [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		14	19
Assets Of Consolidated V I Es [Member] | Residential Mortgage Backed Non Agency [Member] | Mortgage-backed [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		98	108
Assets Of Consolidated V I Es [Member] | Commercial Mortgage Backed Securities [Member] | Mortgage-backed [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		35	36
Assets Of Consolidated V I Es [Member] | Collateralized Debt Obligations [Member] | Asset-backed [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		7	9
Assets Of Consolidated V I Es [Member] | Other Asset Backed [Member] | Asset-backed [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		9	10
Assets Of Consolidated V I Es [Member] | Loans Receivable At Fair Value [Member] | Variable Interest Entity Primary Beneficiary [Member] | Residential Loans Receivable [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		428	759
Assets Of Consolidated V I Es [Member] | Loans Receivable At Fair Value [Member] | Variable Interest Entity Primary Beneficiary [Member] | Corporate Loans Receivable [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		0	920
Assets Of Consolidated V I Es [Member] | Currency Derivatives [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		14	19
Assets Of Consolidated V I Es [Member] | Cash And Cash Equivalents [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		12	24
Assets Of Consolidated V I Es [Member] | Other [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		15	14
Derivative Liabilities [Member] | Credit Derivatives [Member] | Insured Derivatives [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis		29	65
Derivative Liabilities [Member] | Interest Rate Derivatives [Member] | Non Insured Derivatives [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis		137	193
Derivative Liabilities [Member] | Other Derivatives [Member] | Non Insured Derivatives [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis		7	4
Other Liabilities [Member] | Warrant [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis			6
Other Liabilities [Member] | Other Payable [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis		5	7
Liabilities Of Consolidated Vies [Member] | Variable Interest Entity Notes [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis		709	1,069
Fair Value Inputs Level 1 [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		1,137	1,608
Fair Value Inputs Level 1 [Member] | Money Market Securities [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		147	180
Fair Value Inputs Level 1 [Member] | Perpetual Debt And Equity Securities [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		26	26
Fair Value Inputs Level 1 [Member] | Cash And Cash Equivalents [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		167	122
Fair Value Inputs Level 1 [Member] | Fixed Maturities [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		785	1,256
Fair Value Inputs Level 1 [Member] | Fixed Maturities [Member] | U S Treasury And Government [Member] | Other Fixed Maturity Investments [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		765	1,256
Fair Value Inputs Level 1 [Member] | Fixed Maturities [Member] | Corporate Obligations [Member] | Other Fixed Maturity Investments [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		20
Fair Value Inputs Level 1 [Member] | Assets Of Consolidated V I Es [Member] | Cash And Cash Equivalents [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		12	24
Fair Value Inputs Level 2 [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		3,320	3,272
Fair value financial liabilities measured on recurring basis		466	864
Fair Value Inputs Level 2 [Member] | Perpetual Debt And Equity Securities [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		38	37
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		3,123	3,058
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | U S Treasury And Government [Member] | Other Fixed Maturity Investments [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		89	96
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | State and municipal bonds [Member] | Other Fixed Maturity Investments [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		757	858
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | Foreign Government Debt [Member] | Other Fixed Maturity Investments [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		11	10
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | Corporate Obligations [Member] | Other Fixed Maturity Investments [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		1,603	1,338
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | Residential Mortgage Backed Agency [Member] | Mortgage-backed [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		220	368
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | Residential Mortgage Backed Non Agency [Member] | Mortgage-backed [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		30	32
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | Commercial Mortgage Backed Securities [Member] | Mortgage-backed [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		50	60
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | Collateralized Debt Obligations [Member] | Asset-backed [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		146	118
Fair Value Inputs Level 2 [Member] | Fixed Maturities [Member] | Other Asset Backed [Member] | Asset-backed [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		217	178
Fair Value Inputs Level 2 [Member] | Derivative Assets [Member] | Interest Rate Derivatives [Member] | Non Insured Derivatives [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		2	2
Fair Value Inputs Level 2 [Member] | Assets Of Consolidated V I Es [Member] | Corporate Obligations [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		9	19
Fair Value Inputs Level 2 [Member] | Assets Of Consolidated V I Es [Member] | Residential Mortgage Backed Non Agency [Member] | Mortgage-backed [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		98	108
Fair Value Inputs Level 2 [Member] | Assets Of Consolidated V I Es [Member] | Commercial Mortgage Backed Securities [Member] | Mortgage-backed [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		35	30
Fair Value Inputs Level 2 [Member] | Assets Of Consolidated V I Es [Member] | Collateralized Debt Obligations [Member] | Asset-backed [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		6	8
Fair Value Inputs Level 2 [Member] | Assets Of Consolidated V I Es [Member] | Other Asset Backed [Member] | Asset-backed [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		9	10
Fair Value Inputs Level 2 [Member] | Derivative Liabilities [Member] | Credit Derivatives [Member] | Insured Derivatives [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis		2	2
Fair Value Inputs Level 2 [Member] | Derivative Liabilities [Member] | Interest Rate Derivatives [Member] | Non Insured Derivatives [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis		137	193
Fair Value Inputs Level 2 [Member] | Other Liabilities [Member] | Warrant [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis			6
Fair Value Inputs Level 2 [Member] | Liabilities Of Consolidated Vies [Member] | Variable Interest Entity Notes [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis		327	663
Fair Value Inputs Level 3 [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		889	2,140
Fair value financial liabilities measured on recurring basis		544	595
Fair Value Inputs Level 3 [Member] | Medium Term Notes [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis	[2]	123	115
Fair Value Inputs Level 3 [Member] | Fixed Maturities [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		11	14
Fair Value Inputs Level 3 [Member] | Fixed Maturities [Member] | Corporate Obligations [Member] | Other Fixed Maturity Investments [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis	[2]		2
Fair Value Inputs Level 3 [Member] | Fixed Maturities [Member] | Commercial Mortgage Backed Securities [Member] | Mortgage-backed [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis	[2]	7	7
Fair Value Inputs Level 3 [Member] | Fixed Maturities [Member] | Other Asset Backed [Member] | Asset-backed [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis	[2]	4	5
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Variable Interest Entity Primary Beneficiary [Member] | Loan Repurchase Commitments [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		415	407
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Corporate Obligations [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis	[2]	5
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Commercial Mortgage Backed Securities [Member] | Mortgage-backed [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis	[2]		6
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Collateralized Debt Obligations [Member] | Asset-backed [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis	[2]	1	1
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Loans Receivable At Fair Value [Member] | Variable Interest Entity Primary Beneficiary [Member] | Residential Loans Receivable [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis		428	759
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Loans Receivable At Fair Value [Member] | Variable Interest Entity Primary Beneficiary [Member] | Corporate Loans Receivable [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis	[2]	0	920
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Currency Derivatives [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis	[2]	14	19
Fair Value Inputs Level 3 [Member] | Assets Of Consolidated V I Es [Member] | Other [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial assets measured on recurring basis	[2]	15	14
Fair Value Inputs Level 3 [Member] | Derivative Liabilities [Member] | Credit Derivatives [Member] | Insured Derivatives [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis		27	63
Fair Value Inputs Level 3 [Member] | Derivative Liabilities [Member] | Other Derivatives [Member] | Non Insured Derivatives [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis		7	4
Fair Value Inputs Level 3 [Member] | Other Liabilities [Member] | Other Payable [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis	[2]	5	7
Fair Value Inputs Level 3 [Member] | Liabilities Of Consolidated Vies [Member] | Variable Interest Entity Notes [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Fair value financial liabilities measured on recurring basis		$ 382	$ 406
[1]	Investment that was measured at fair value by applying the net asset value per share practical expedient, and was required not to be classified in the fair value hierarchy.
[2]	Unobservable inputs are either not developed by the Company or do not significantly impact the overall fair values of the aggregate financial assets and liabilities.

Fair Value Of Financial Instr_6

Fair Value Of Financial Instruments (Fair Value Hierarchy Table Presents The Company's Assets And Liabilities At Fair Value Not Recorded On The Company's Consolidated Balance Sheet) (Detail) - USD ($) $ in Millions		Sep. 30, 2018	Dec. 31, 2017
Variable Interest Entity Primary Beneficiary [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Investments held-to-maturity, fair value		$ 901	$ 916
Carrying Reported Amount Fair Value Disclosure [Member] | Value Disclosed At Fair Value Not Recorded At Fair Value [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Other investments		1	2
Accrued investment income	[1]		0
Total assets		891	892
Investment agreements		314	337
Medium-term notes		615	650
Long-term debt		2,218	2,121
Payable for investments purchased	[2]		0
Total liabilities		4,398	4,328
Gross		100	1,220
Ceded		38	39
Carrying Reported Amount Fair Value Disclosure [Member] | Value Disclosed At Fair Value Not Recorded At Fair Value [Member] | Variable Interest Entity Primary Beneficiary [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Investments held-to-maturity, fair value		890	890
Variable interest entity notes		1,251	1,220
Fair Value [Member] | Value Disclosed At Fair Value Not Recorded At Fair Value [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Other investments	[1]	1	2
Accrued investment income	[1]		0
Total assets		902	918
Investment agreements		381	433
Medium-term notes		416	406
Long-term debt		1,132	1,002
Payable for investments purchased	[2]		0
Total liabilities		3,211	3,109
Gross		1,231	1,785
Ceded		68	61
Fair Value [Member] | Value Disclosed At Fair Value Not Recorded At Fair Value [Member] | Variable Interest Entity Primary Beneficiary [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Investments held-to-maturity, fair value		901	916
Variable interest entity notes		1,282	1,268
Fair Value [Member] | Value Disclosed At Fair Value Not Recorded At Fair Value [Member] | Fair Value Inputs Level 2 [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Other investments	[1]	1	2
Accrued investment income	[1]		0
Total assets		1	2
Long-term debt		1,132	1,002
Payable for investments purchased	[2]		0
Total liabilities		1,514	1,354
Fair Value [Member] | Value Disclosed At Fair Value Not Recorded At Fair Value [Member] | Fair Value Inputs Level 2 [Member] | Variable Interest Entity Primary Beneficiary [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Variable interest entity notes		382	352
Fair Value [Member] | Value Disclosed At Fair Value Not Recorded At Fair Value [Member] | Fair Value Inputs Level 3 [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Total assets		901	916
Investment agreements		381	433
Medium-term notes		416	406
Total liabilities		1,697	1,755
Gross		1,231	1,785
Ceded		68	61
Fair Value [Member] | Value Disclosed At Fair Value Not Recorded At Fair Value [Member] | Fair Value Inputs Level 3 [Member] | Variable Interest Entity Primary Beneficiary [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Investments held-to-maturity, fair value		901	916
Variable interest entity notes		$ 900	$ 916
[1]	Reported within "Other assets" on MBIA's consolidated balance sheets.
[2]	Reported within "Other liabilities" on MBIA's consolidated balance sheets.

Fair Value Of Financial Instr_7

Fair Value Of Financial Instruments (Changes In Level 3 Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Detail) - Fair Value Inputs Level 3 [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value assets	$ 1,138	$ 2,122	$ 2,140	$ 1,552
Realized gains/(losses), assets	0	0	0	0
Unrealized gains/(losses) included in earnings, assets	23	8	43	65
Unrealized gains/(losses) included in OCI, assets	0	0	0	2
Foreign exchange recognized in OCI or earnings, assets	(2)	1	(2)	(4)
Purchases, assets	0	17	5	736
Issuances, assets	0	0	0	0
Settlements, assets	(24)	(64)	(115)	(268)
Sales, assets	(251)	(3)	(1,178)	(3)
Transfers into level 3, assets	7	0	13	18
Transfers out of level 3, assets	(2)	(7)	(17)	(24)
Ending balance, fair value assets	889	2,074	889	2,074
Change in unrealized gains/(losses) for the period included in earnings for assets still held, assets	22	9	27	61
Beginning balance, fair value liabilities	578	698	595	661
Realized gains/(losses), liabilities	11	7	66	41
Unrealized gains/(losses included in earnings, liabilities	1	(2)	(44)	98
Unrealized gains/(losses) included in OCI, liabilities	0	0	41	0
Foreign exchange recognized in OCI or earnings, liabilities	4	5	(4)	13
Purchases, liabilities	0	6	0	6
Issuances, liabilities	1	0	7	0
Settlements, liabilities	(51)	(21)	(117)	(126)
Sales, liabilities	0	(51)	0	(51)
Transfers into Level 3, liabilities	0	0	0	0
Transfers out of Level 3, liabilities	0	0	0	0
Ending balance, fair value liabilities	544	642	544	642
Change in unrealized gains/(losses) for the period included in earnings for liabilities still held, liabilities	5	3	(48)	113
Residential Prime Financing Receivable [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value assets	683	815	759	916
Unrealized gains/(losses) included in earnings, assets	20	2	26	29
Settlements, assets	(24)	(58)	(106)	(186)
Sales, assets	(251)		(251)
Ending balance, fair value assets	428	759	428	759
Change in unrealized gains/(losses) for the period included in earnings for assets still held, assets	21	2	23	29
Corporate Loans Receivable [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value assets		875	920	150
Unrealized gains/(losses) included in earnings, assets		4	11	36
Purchases, assets				719
Settlements, assets		(6)	(6)	(32)
Sales, assets			(925)
Ending balance, fair value assets		873		873
Change in unrealized gains/(losses) for the period included in earnings for assets still held, assets		4		36
Loan Repurchase Commitments [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value assets	415	407	407	404
Unrealized gains/(losses) included in earnings, assets		(1)	8	2
Ending balance, fair value assets	415	406	415	406
Change in unrealized gains/(losses) for the period included in earnings for assets still held, assets		(1)	8	2
State and municipal bonds [Member]
Accounts Notes And Loans Receivable [Line Items]
Transfers into level 3, assets				1
Transfers out of level 3, assets				(1)
Corporate Obligations [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value assets			2	2
Transfers out of level 3, assets			(2)	(2)
Corporate Obligations [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value assets	5
Settlements, assets			(1)	(2)
Transfers into level 3, assets			6	6
Transfers out of level 3, assets				(4)
Ending balance, fair value assets	5		5
Commercial Mortgage Backed Securities [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value assets		7	7
Transfers into level 3, assets	7		7	7
Transfers out of level 3, assets		(7)	(7)	(7)
Ending balance, fair value assets	7		7
Commercial Mortgage Backed Securities [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value assets		3	6
Sales, assets		(3)		(3)
Transfers into level 3, assets				3
Transfers out of level 3, assets			(6)
Collateralized Debt Obligations [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value assets				15
Settlements, assets				(7)
Transfers out of level 3, assets				(8)
Collateralized Debt Obligations [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value assets	1	1	1	1
Ending balance, fair value assets	1	1	1	1
Other Asset Backed [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value assets	6	5	5	44
Unrealized gains/(losses) included in OCI, assets				2
Purchases, assets			5
Settlements, assets			(2)	(41)
Sales, assets			(2)
Transfers out of level 3, assets	(2)		(2)
Ending balance, fair value assets	4	5	4	5
Other Asset Backed [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value assets				1
Transfers into level 3, assets				1
Transfers out of level 3, assets				(2)
Medium Term Notes [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value liabilities	149	123	115	101
Realized gains/(losses), liabilities	(5)		(5)
Unrealized gains/(losses included in earnings, liabilities	(1)	(1)	(1)	13
Unrealized gains/(losses) included in OCI, liabilities	11		51
Foreign exchange recognized in OCI or earnings, liabilities	(1)	5	(7)	13
Settlements, liabilities	(30)		(30)
Ending balance, fair value liabilities	123	127	123	127
Change in unrealized gains/(losses) for the period included in earnings for liabilities still held, liabilities	(2)	4	(8)	26
Credit Derivatives [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value liabilities	31	80	63	64
Realized gains/(losses), liabilities	6	7	49	41
Unrealized gains/(losses included in earnings, liabilities	(4)	(6)	(36)	10
Settlements, liabilities	(6)	(7)	(49)	(41)
Ending balance, fair value liabilities	27	74	27	74
Change in unrealized gains/(losses) for the period included in earnings for liabilities still held, liabilities	(4)	(6)	(36)	12
Other Derivative Liabilities [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value liabilities	4	4	4	20
Unrealized gains/(losses included in earnings, liabilities	3		3	18
Settlements, liabilities				(34)
Ending balance, fair value liabilities	7	4	7	4
Change in unrealized gains/(losses) for the period included in earnings for liabilities still held, liabilities	3		3	18
Variable Interest Entity Notes [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value liabilities	389	491	406	476
Realized gains/(losses), liabilities	10		22
Unrealized gains/(losses included in earnings, liabilities	3	4	(12)	56
Unrealized gains/(losses) included in OCI, liabilities	(11)		(10)
Foreign exchange recognized in OCI or earnings, liabilities	5		3
Issuances, liabilities	1		7
Settlements, liabilities	(15)	(14)	(34)	(51)
Sales, liabilities		(51)		(51)
Ending balance, fair value liabilities	382	430	382	430
Change in unrealized gains/(losses) for the period included in earnings for liabilities still held, liabilities	8	4	(9)	56
Currency Derivatives [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value assets	14	9	19	19
Unrealized gains/(losses) included in earnings, assets	2	3	(3)	(2)
Foreign exchange recognized in OCI or earnings, assets	(2)	1	(2)	(4)
Ending balance, fair value assets	14	13	14	13
Change in unrealized gains/(losses) for the period included in earnings for assets still held, assets		4	(5)	(6)
Other Assets [Member] | Variable Interest Entity Primary Beneficiary [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value assets	14		14
Unrealized gains/(losses) included in earnings, assets	1		1
Purchases, assets		17		17
Ending balance, fair value assets	15	17	15	17
Change in unrealized gains/(losses) for the period included in earnings for assets still held, assets	1		1
Other Payable [Member]
Accounts Notes And Loans Receivable [Line Items]
Beginning balance, fair value liabilities	5		7
Unrealized gains/(losses included in earnings, liabilities		1	2	1
Purchases, liabilities		6		6
Settlements, liabilities			(4)
Ending balance, fair value liabilities	$ 5	7	5	7
Change in unrealized gains/(losses) for the period included in earnings for liabilities still held, liabilities		$ 1	$ 2	$ 1

Fair Value Of Financial Instr_8

Fair Value Of Financial Instruments (Realized And Unrealized Gains And Losses Included In Earnings Pertaining To Level 3 Assets And Liabilities) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unrealized gains (losses) on insured derivatives			$ 36	$ (10)
Net gains (losses) on financial instruments at fair value and foreign exchange	$ 5	$ (11)	18	(55)
Other net realized gains (losses)	1	(1)	0	36
Net investment losses related to other-than-temporary impairments	(1)	(71)	(3)	(84)
Fair Value Inputs Level 3 [Member] | Total Gains Losses Included In Earnings [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unrealized gains (losses) on insured derivatives	4	6	36	(10)
Realized gains and other settlements on insured derivatives	(6)	(7)	(49)	(41)
Net gains (losses) on financial instruments at fair value and foreign exchange	4	(4)	10	(44)
Other net realized gains (losses)	0	(1)	(2)	(1)
Total revenues	5	(1)	23	(91)
Fair Value Inputs Level 3 [Member] | Change In Unrealized Gains Losses For Period Included In Earnings For Assets And Liabilities Still Held [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unrealized gains (losses) on insured derivatives	4	6	36	(12)
Realized gains and other settlements on insured derivatives	0	0	0	0
Net gains (losses) on financial instruments at fair value and foreign exchange	(1)	(4)	5	(44)
Other net realized gains (losses)	0	(1)	(2)	(1)
Total revenues	17	6	75	(52)
Fair Value Inputs Level 3 [Member] | Variable Interest Entity Primary Beneficiary [Member] | Total Gains Losses Included In Earnings [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	3	5	28	5
Fair Value Inputs Level 3 [Member] | Variable Interest Entity Primary Beneficiary [Member] | Change In Unrealized Gains Losses For Period Included In Earnings For Assets And Liabilities Still Held [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	$ 14	$ 5	$ 36	$ 5

Fair Value Of Financial Instr_9

Fair Value Of Financial Instruments (Gains And Losses On Fair Value Option Included In The Company's Consolidated Statements Of Operations) (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Accounts Notes And Loans Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange		$ 5	$ (11)	$ 18	$ (55)
Other net realized gains (losses)		1	(1)	0	36
Non Variable Interest Entity [Member]
Accounts Notes And Loans Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange		5	(11)	18	(55)
Other net realized gains (losses)		1	(1)	0	36
Variable Interest Entity [Member]
Accounts Notes And Loans Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange		12	21	29	2
Other net realized gains (losses)		(33)	0	(126)	28
Variable Interest Entity [Member] | Loan Repurchase Commitments [Member]
Accounts Notes And Loans Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	[1]	0	(1)	9	3
Investments Carried At Fair Value [Member] | Non Variable Interest Entity [Member]
Accounts Notes And Loans Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	[2]	1	2	(4)	8
Fixed Maturity Securities Held At Fair Value - VIE [Member] | Variable Interest Entity [Member]
Accounts Notes And Loans Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	[1]	(7)	(2)	(19)	(16)
Residential Mortgage Loans [Member] | Variable Interest Entity [Member]
Accounts Notes And Loans Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	[1]	(3)	(55)	(79)	(157)
Corporate Loans [Member] | Variable Interest Entity [Member]
Accounts Notes And Loans Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	[1]	0	(2)	11	4
Other Assets [Member] | Variable Interest Entity [Member]
Accounts Notes And Loans Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	[1]	1	0	1	0
Medium Term Notes [Member] | Non Variable Interest Entity [Member]
Accounts Notes And Loans Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	[2]	7	(4)	14	(26)
Variable Interest Entity Notes [Member] | Variable Interest Entity [Member]
Accounts Notes And Loans Receivable [Line Items]
Net gains (losses) on financial instruments at fair value and foreign exchange	[1]	23	70	106	160
Other Liabilities [Member] | Non Variable Interest Entity [Member]
Accounts Notes And Loans Receivable [Line Items]
Other net realized gains (losses)	[3]	$ 0	$ (1)	$ (2)	$ (1)
[1]	Reported within Net gains (losses) of financial instruments at fair value and foreign exchange-VIE on MBIA's consolidated statements of operations.
[2]	Reported within Net gains (losses) of financial instruments at fair value and foreign exchange on MBIA's consolidated statements of operations.
[3]	Reported within "Other net realized gains (losses)" on MBIA's consolidated statements of operations.

Fair Value Of Financial Inst_10

Fair Value Of Financial Instruments (Aggregate Fair Value And Remaining Contractual Principal Balance Outstanding On Fair Value Option) (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Variable Interest Entity [Member]
Schedule Of Fair Value Of Separate Accounts By Major Category Of Investment [Line Items]
Loans receivable, contractual outstanding principal	$ 555	$ 2,296
Loans receivable, fair value	428	1,679
Loans receivable, difference	127	617
Residential Mortgage Loans [Member] | Variable Interest Entity [Member]
Schedule Of Fair Value Of Separate Accounts By Major Category Of Investment [Line Items]
Loans receivable, contractual outstanding principal	390	732
Loans receivable, 90 days or more past due, contractual outstanding principal	165	170
Loans receivable, fair value	389	727
Loans receivable, 90 days or more past due, fair value	39	32
Loans receivable, difference	1	5
Loans receivable, 90 days or more past due, difference	126	138
Corporate Loans [Member] | Variable Interest Entity [Member]
Schedule Of Fair Value Of Separate Accounts By Major Category Of Investment [Line Items]
Loans receivable, 90 days or more past due, contractual outstanding principal	0	1,394
Loans receivable, 90 days or more past due, fair value	0	920
Loans receivable, 90 days or more past due, difference	0	474
Medium Term Notes [Member] | Non Variable Interest Entity [Member]
Schedule Of Fair Value Of Separate Accounts By Major Category Of Investment [Line Items]
Long-term debt instruments, contractual outstanding principal	139	180
Long-term debt instruments, fair value	123	115
Long-term debt instruments, difference	16	65
Variable Interest Entity Notes [Member] | Variable Interest Entity [Member]
Schedule Of Fair Value Of Separate Accounts By Major Category Of Investment [Line Items]
Long-term debt instruments, contractual outstanding principal	1,525	1,882
Long-term debt instruments, fair value	709	1,069
Long-term debt instruments, difference	$ 816	$ 813

Investments (Narrative) (Detail

Investments (Narrative) (Detail) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2018USD ($)security	Dec. 31, 2017USD ($)security
Schedule Of Investments [Line Items]
Fair value of securities on deposit with various regulatory authorities | $	$ 10	$ 10
Fair value of securities pledged as collateral | $	$ 320	$ 353
Weighted average contractual maturity period in years for securities in an unrealized loss position	13 years	12 years
Number of securities in unrealized loss position for a continuous 12 month period | security	131	133
Rate that a security's fair value is below book value	5.00%	5.00%
Fair Value Below Book Value Greater Than Five Percent [Member]
Schedule Of Investments [Line Items]
Number of securities in unrealized loss position for a continuous 12 month period | security	75	24

Investments (Amortized Cost And

Investments (Amortized Cost And Fair Value Of Available-For-Sale and Held-To-Maturity Investment Portfolios) (Detail) - USD ($) $ in Millions		Sep. 30, 2018	Dec. 31, 2017
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost		$ 3,852	$ 4,438
Gross unrealized gains		139	91
Gross unrealized losses		(168)	(106)
Total available-for-sale, fair value		3,823	4,423
Other-than-temporary impairments	[1]	(20)	(71)
Variable Interest Entity Primary Beneficiary [Member]
Held To Maturity Securities [Abstract]
Total held-to-maturity, amortized cost		890	890
Gross unrealized gains		13	26
Gross unrealized losses		(2)	0
Total held-to-maturity investments, fair value		901	916
Other-Than-Temporary Impairments	[1]	0	0
Corporate Obligations [Member] | Variable Interest Entity Primary Beneficiary [Member]
Held To Maturity Securities [Abstract]
Total held-to-maturity, amortized cost		890	890
Gross unrealized gains		13	26
Gross unrealized losses		(2)	0
Total held-to-maturity investments, fair value		901	916
Other-Than-Temporary Impairments	[1]	0	0
Money Market Securities [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost		0	179
Gross unrealized gains		0	0
Gross unrealized losses		0	0
Total available-for-sale, fair value		0	179
Other-than-temporary impairments	[1]	0	0
Perpetual Debt And Equity Securities [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost		0	3
Gross unrealized gains		0	1
Gross unrealized losses		0	0
Total available-for-sale, fair value		0	4
Other-than-temporary impairments	[1]	0	0
Fixed Maturities [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost		3,852	4,256
Gross unrealized gains		139	90
Gross unrealized losses		(168)	(106)
Total available-for-sale, fair value		3,823	4,240
Other-than-temporary impairments	[1]	(20)	(71)
Fixed Maturities [Member] | Variable Interest Entity Primary Beneficiary [Member]
Held To Maturity Securities [Abstract]
Total held-to-maturity, amortized cost		890
Total held-to-maturity investments, fair value		901
Fixed Maturities [Member] | U S Treasury And Government [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost		843	1,317
Gross unrealized gains		20	34
Gross unrealized losses		(19)	(6)
Total available-for-sale, fair value		844	1,345
Other-than-temporary impairments	[1]	0	0
Fixed Maturities [Member] | US States And Political Subdivisions [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost		659	840
Gross unrealized gains		111	29
Gross unrealized losses		(14)	(12)
Total available-for-sale, fair value		756	857
Other-than-temporary impairments	[1]	47	0
Fixed Maturities [Member] | Foreign Governments [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost		10	10
Gross unrealized gains		0	0
Gross unrealized losses		0	0
Total available-for-sale, fair value		10	10
Other-than-temporary impairments	[1]	0	0
Fixed Maturities [Member] | Corporate Obligations [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost		1,672	1,332
Gross unrealized gains		6	25
Gross unrealized losses		(122)	(80)
Total available-for-sale, fair value		1,556	1,277
Other-than-temporary impairments	[1]	(68)	(72)
Fixed Maturities [Member] | Residential Mortgage-Backed Agency [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost		222	365
Gross unrealized gains		0	1
Gross unrealized losses		(7)	(4)
Total available-for-sale, fair value		215	362
Other-than-temporary impairments	[1]	0	0
Fixed Maturities [Member] | Residential Mortgage-Backed Non-Agency [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost		32	35
Gross unrealized gains		1	1
Gross unrealized losses		(3)	(4)
Total available-for-sale, fair value		30	32
Other-than-temporary impairments	[1]	0	0
Fixed Maturities [Member] | Commercial Mortgage-Backed [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost		57	66
Gross unrealized gains		0	0
Gross unrealized losses		(2)	0
Total available-for-sale, fair value		55	66
Other-than-temporary impairments	[1]	0	0
Fixed Maturities [Member] | Collateralized Debt Obligations [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost		143	116
Gross unrealized gains		0	0
Gross unrealized losses		0	0
Total available-for-sale, fair value		143	116
Other-than-temporary impairments	[1]	0	0
Fixed Maturities [Member] | Other Asset-Backed [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost		214	175
Gross unrealized gains		1	0
Gross unrealized losses		(1)	0
Total available-for-sale, fair value		214	175
Other-than-temporary impairments	[1]	$ 1	$ 1
[1]	Represents unrealized gains or losses on other than temporarily impaired securities recognized in AOCI, which includes the non-credit component of impairments, as well as all subsequent changes in fair value of such impaired securities reported in AOCI.

Investments (Distribution By Co

Investments (Distribution By Contractual Maturity Of Available-For-Sale and Held-To-Maturity Investments) (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Variable Interest Entity Primary Beneficiary [Member]
Held To Maturity Securities [Abstract]
Total held-to-maturity, amortized cost	$ 890	$ 890
Held-To-Maturity Securities Fair Value	901	$ 916
Fixed Maturities [Member]
Available For Sale Securities [Abstract]
Due in one year or less	790
Due after one year through five years	677
Due after five years through ten years	670
Due after ten years	1,047
Mortgage-Backed and Asset-Backed	668
Total Available-For-Sale, amortized cost	3,852
Due in one year or less	802
Due after one year through five years	702
Due after five years through ten years	589
Due after ten years	1,073
Mortgage-Backed and Asset-Backed	657
Total Available-For-Sale, fair value	3,823
Fixed Maturities [Member] | Variable Interest Entity Primary Beneficiary [Member]
Held To Maturity Securities [Abstract]
Due in one year or less	0
Due after one year through five years	0
Due after five years through ten years	0
Due after ten years	890
Mortgage-Backed and Asset-Backed	0
Total held-to-maturity, amortized cost	890
Due in one year or less	0
Due after one year through five years	0
Due after five years through ten years	0
Due after ten years	901
Mortgage-Backed and Asset-Backed	0
Held-To-Maturity Securities Fair Value	$ 901

Investments (Gross Unrealized L

Investments (Gross Unrealized Losses Related To Available-For-Sale And Held-To-Maturity Investments) (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Available For Sale Securities [Abstract]
Less than 12 months, fair value	$ 1,955
Less than 12 months, unrealized losses	(51)
12 months or longer, fair value	700
12 months or longer, unrealized losses	(117)
Total available-for-sale, fair value	2,655
Total available-for-sale, unrealized losses	(168)
Variable Interest Entity Primary Beneficiary [Member]
Held To Maturity Securities [Abstract]
Less than 12 months, fair value	313
Less than 12 months, unrealized losses	(2)
12 months or longer, fair value	0
12 months or longer, unrealized losses	0
Total held-to-maturity, fair value	313
Total held-to-maturity, unrealized losses	(2)
Corporate Obligations [Member] | Variable Interest Entity Primary Beneficiary [Member]
Held To Maturity Securities [Abstract]
Less than 12 months, fair value	313
Less than 12 months, unrealized losses	(2)
12 months or longer, fair value	0
12 months or longer, unrealized losses	0
Total held-to-maturity, fair value	313
Total held-to-maturity, unrealized losses	(2)
Fixed Maturities [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	1,955	$ 1,204
Less than 12 months, unrealized losses	(51)	(13)
12 months or longer, fair value	700	617
12 months or longer, unrealized losses	(117)	(93)
Total available-for-sale, fair value	2,655	1,821
Total available-for-sale, unrealized losses	(168)	(106)
Fixed Maturities [Member] | U S Treasury And Government [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	396	353
Less than 12 months, unrealized losses	(7)	(1)
12 months or longer, fair value	206	124
12 months or longer, unrealized losses	(12)	(5)
Total available-for-sale, fair value	602	477
Total available-for-sale, unrealized losses	(19)	(6)
Fixed Maturities [Member] | US States And Political Subdivisions [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	92	203
Less than 12 months, unrealized losses	(3)	(8)
12 months or longer, fair value	123	116
12 months or longer, unrealized losses	(11)	(4)
Total available-for-sale, fair value	215	319
Total available-for-sale, unrealized losses	(14)	(12)
Fixed Maturities [Member] | Foreign Government Debt [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	9	8
Less than 12 months, unrealized losses	0	0
12 months or longer, fair value	0	0
12 months or longer, unrealized losses	0	0
Total available-for-sale, fair value	9	8
Total available-for-sale, unrealized losses	0	0
Fixed Maturities [Member] | Corporate Obligations [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	1,116	425
Less than 12 months, unrealized losses	(38)	(3)
12 months or longer, fair value	213	163
12 months or longer, unrealized losses	(84)	(77)
Total available-for-sale, fair value	1,329	588
Total available-for-sale, unrealized losses	(122)	(80)
Fixed Maturities [Member] | Residential Mortgage Backed Agency [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	119	105
Less than 12 months, unrealized losses	(2)	(1)
12 months or longer, fair value	95	156
12 months or longer, unrealized losses	(5)	(3)
Total available-for-sale, fair value	214	261
Total available-for-sale, unrealized losses	(7)	(4)
Fixed Maturities [Member] | Residential Mortgage Backed Non Agency [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	0	0
Less than 12 months, unrealized losses	0	0
12 months or longer, fair value	14	14
12 months or longer, unrealized losses	(3)	(4)
Total available-for-sale, fair value	14	14
Total available-for-sale, unrealized losses	(3)	(4)
Fixed Maturities [Member] | Commercial Mortgage Backed Securities [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	29	27
Less than 12 months, unrealized losses	0	0
12 months or longer, fair value	19	5
12 months or longer, unrealized losses	(2)	0
Total available-for-sale, fair value	48	32
Total available-for-sale, unrealized losses	(2)	0
Fixed Maturities [Member] | Collateralized Debt Obligations [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	73	12
Less than 12 months, unrealized losses	0	0
12 months or longer, fair value	0	0
12 months or longer, unrealized losses	0	0
Total available-for-sale, fair value	73	12
Total available-for-sale, unrealized losses	0	0
Fixed Maturities [Member] | Other Asset Backed [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	121	71
Less than 12 months, unrealized losses	(1)	0
12 months or longer, fair value	30	39
12 months or longer, unrealized losses	0	0
Total available-for-sale, fair value	151	110
Total available-for-sale, unrealized losses	$ (1)	$ 0

Investments (Distribution Of Se

Investments (Distribution Of Securities By Percentage Of Fair Value Below Book Value By More Than 5% For A Continuous Twelve Month Period Or Longer) (Detail) $ in Millions	Sep. 30, 2018USD ($)security	Dec. 31, 2017USD ($)
Available For Sale Securities [Abstract]
Fixed-maturity securities held as available-for-sale, amortized cost	$ 3,852	$ 4,438
Available For Sale Securities	$ 3,823	$ 4,423
> 5% To 15% [Member]
Held To Maturity Securities [Abstract]
Percentage Of Fair Value Below Book Value Minimum	5.00%
Percentage Of Fair Value Below Book Value Maximum	15.00%
> 5% To 15% [Member] | Unrealized loss position > 12 months
Available For Sale Securities [Abstract]
Number of available-for-sale securities in unrealized loss position | security	60
Fixed-maturity securities held as available-for-sale, amortized cost	$ 368
Available For Sale Securities	$ 338
> 15% To 25% [Member]
Held To Maturity Securities [Abstract]
Percentage Of Fair Value Below Book Value Minimum	15.00%
Percentage Of Fair Value Below Book Value Maximum	25.00%
> 15% To 25% [Member] | Unrealized loss position > 12 months
Available For Sale Securities [Abstract]
Number of available-for-sale securities in unrealized loss position | security	11
Fixed-maturity securities held as available-for-sale, amortized cost	$ 61
Available For Sale Securities	$ 50
> 25% To 50% [Member]
Held To Maturity Securities [Abstract]
Percentage Of Fair Value Below Book Value Minimum	25.00%
Percentage Of Fair Value Below Book Value Maximum	50.00%
> 25% To 50% [Member] | Unrealized loss position > 12 months
Available For Sale Securities [Abstract]
Number of available-for-sale securities in unrealized loss position | security	0
Fixed-maturity securities held as available-for-sale, amortized cost	$ 0
Available For Sale Securities	$ 0
> 50% [Member]
Held To Maturity Securities [Abstract]
Percentage Of Fair Value Below Book Value Minimum	50.00%
> 50% [Member] | Unrealized loss position > 12 months
Available For Sale Securities [Abstract]
Number of available-for-sale securities in unrealized loss position | security	4
Fixed-maturity securities held as available-for-sale, amortized cost	$ 100
Available For Sale Securities	$ 32
Greater Than 5% [Member] | Unrealized loss position > 12 months
Available For Sale Securities [Abstract]
Number of available-for-sale securities in unrealized loss position | security	75
Fixed-maturity securities held as available-for-sale, amortized cost	$ 529
Available For Sale Securities	$ 420

Investments (Credit Losses Reco

Investments (Credit Losses Recognized In Earnings Related To OTTI Losses Recognized In Accumulated Other Comprehensive Income (Loss)) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Other than temporary impairment credit lossesfor available for sale securities rollforward [Abstract]
Beginning Balance	$ 34	$ 42	$ 32	$ 29
Additions For Credit Loss Impairments Recognized In The Current Period On Securities Not Previous Impaired	0	0	0	11
Additions For Credit Loss Impairments Recognized In The Current Period On Securities Previously Impaired	1	2	3	4
Reductions For Credit Loss Impairments Previously Recognized On Securities Sold During The Period	0	(2)	0	(2)
Reductions For Credit Loss Impairments Previously Recognized On Securities Impaired To Fair Value During The Period	0	(11)	0	(11)
Ending Balance	$ 35	$ 31	$ 35	$ 31

Investments (Securities Held In

Investments (Securities Held In Unrealized Loss Position And Insured By Financial Guarantor) (Detail) $ in Millions	Sep. 30, 2018USD ($)
Schedule Of Investments [Line Items]
Total Available-For-Sale, Fair Value	$ 2,655
Wrapped Securities [Member]
Schedule Of Investments [Line Items]
Total Available-For-Sale, Fair Value	92	[1]
Gross unrealized losses	(15)	[1]
Loss and loss adjustment expense reserves	14	[2]
Mortgage-backed [Member] | Wrapped Securities [Member] | Mbia Corp And National [Member]
Schedule Of Investments [Line Items]
Total Available-For-Sale, Fair Value	14	[1]
Gross unrealized losses	(3)	[1]
Loss and loss adjustment expense reserves	14	[2]
Corporate Obligations [Member] | Wrapped Securities [Member] | Mbia Corp And National [Member]
Schedule Of Investments [Line Items]
Total Available-For-Sale, Fair Value	70	[1]
Gross unrealized losses	(12)	[1]
Loss and loss adjustment expense reserves	0	[2]
All Other Securities [Member] | Wrapped Securities [Member]
Schedule Of Investments [Line Items]
Total Available-For-Sale, Fair Value	8	[1]
Gross unrealized losses	0	[1]
Loss and loss adjustment expense reserves	0	[2]
All Other Securities [Member] | Wrapped Securities [Member] | Mbia Corp And National [Member]
Schedule Of Investments [Line Items]
Total Available-For-Sale, Fair Value	6	[1]
Gross unrealized losses	0	[1]
Loss and loss adjustment expense reserves	0	[2]
All Other Securities [Member] | Wrapped Securities [Member] | Other Insurers [Member]
Schedule Of Investments [Line Items]
Total Available-For-Sale, Fair Value	2
Gross unrealized losses	0
Loss and loss adjustment expense reserves	$ 0	[2]
[1]	Includes investments insured by MBIA Corp. and National.
[2]	Insurance loss reserve estimates are based on the proportion of par value owned to the total amount of par value insured.

Investments (Net Realized Gains

Investments (Net Realized Gains (Losses) From Sales Of Available-For-Sale Securities) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Investments [Abstract]
Proceeds from sales	$ 583	$ 312	$ 1,647	$ 1,300
Available For Sale Securities Realized Gain Loss [Abstract]
Gross realized gains	1	5	4	24
Gross realized losses	$ (2)	$ (5)	$ (15)	$ (9)

Investments (Portion Of Unreali

Investments (Portion Of Unrealized Gains And Losses On Equity Investmente Held) (Detail) - Equity Securities [Member] - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Gains (losses) on equity investments [Member]
Gain (Loss) on Investments [Line Items]
Realized investment gains (losses)	$ 3	$ 3
Gains (losses) on equity investments sold during the period [Member]
Gain (Loss) on Investments [Line Items]
Realized investment gains (losses)	0	1
Gains (losses) on equity investments still held at the end of the period [Member]
Gain (Loss) on Investments [Line Items]
Realized investment gains (losses)	$ 3	$ 2

Derivative Instruments (Narrati

Derivative Instruments (Narrative) (Detail) $ in Millions	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Derivative [Line Items]
Cash collateral posted to derivative counterparties	$ 0	$ 0
Securities posted as collateral to derivative counterparties	$ 183	$ 237
Number of credit support annexes	1	1
Fair value of Credit Support Annex	$ 2	$ 2

Derivative Instruments (Credit

Derivative Instruments (Credit Derivatives Sold) (Detail) - Insurance Operations [Member] - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivative notional amount	$ 2,638	$ 2,928
Total fair value of credit derivatives	$ (29)	$ (65)
Credit Default Swap [Member]
Derivative [Line Items]
Weighted average remaining expected maturity	3 months 18 days	1 year
Derivative notional amount	$ 77	$ 127
Total fair value of credit derivatives	$ (27)	$ (63)
Insured Swaps [Member]
Derivative [Line Items]
Weighted average remaining expected maturity	15 years 6 months	15 years 6 months
Derivative notional amount	$ 2,561	$ 2,801
Total fair value of credit derivatives	(2)	(2)
Insured Swaps - Held for Sale [Member]
Derivative [Line Items]
Derivative notional amount	0	0
Credit Rating Aaa [Member]
Derivative [Line Items]
Derivative notional amount	0	0
Total fair value of credit derivatives	0	0
Credit Rating Aaa [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Derivative notional amount	0	0
Credit Rating Aaa [Member] | Insured Swaps [Member]
Derivative [Line Items]
Derivative notional amount	0	0
Credit Rating Aaa [Member] | Other Credit Derivatives [Member]
Derivative [Line Items]
Derivative notional amount	0
Credit Rating Aa [Member]
Derivative [Line Items]
Derivative notional amount	107	117
Total fair value of credit derivatives	0	0
Credit Rating Aa [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Derivative notional amount	0	0
Credit Rating Aa [Member] | Insured Swaps [Member]
Derivative [Line Items]
Derivative notional amount	107	117
Credit Rating Aa [Member] | Other Credit Derivatives [Member]
Derivative [Line Items]
Derivative notional amount	0
Credit Rating A [Member]
Derivative [Line Items]
Derivative notional amount	1,539	1,818
Total fair value of credit derivatives	(1)	(1)
Credit Rating A [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Derivative notional amount	0	0
Credit Rating A [Member] | Insured Swaps [Member]
Derivative [Line Items]
Derivative notional amount	1,539	1,818
Credit Rating A [Member] | Other Credit Derivatives [Member]
Derivative [Line Items]
Derivative notional amount	0
Credit Rating Bbb [Member]
Derivative [Line Items]
Derivative notional amount	915	846
Total fair value of credit derivatives	(1)	(1)
Credit Rating Bbb [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Derivative notional amount	0	0
Credit Rating Bbb [Member] | Insured Swaps [Member]
Derivative [Line Items]
Derivative notional amount	915	846
Credit Rating Bbb [Member] | Insured Swaps - Held for Sale [Member]
Derivative [Line Items]
Derivative notional amount	0	0
Credit Rating Below Investment Grade [Member]
Derivative [Line Items]
Derivative notional amount	77	147
Total fair value of credit derivatives	(27)	(63)
Credit Rating Below Investment Grade [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Derivative notional amount	77	127
Credit Rating Below Investment Grade [Member] | Insured Swaps [Member]
Derivative [Line Items]
Derivative notional amount	$ 0	$ 20

Derivative Instruments (Total F

Derivative Instruments (Total Fair Value Of Company's Derivative Assets And Liabilities By Instrument And Balance Sheet Location, Before Counterparty Netting) (Detail) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Millions		Sep. 30, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivative notional amount		$ 3,769	$ 4,100
Derivative Liabilities [Member]
Derivative [Line Items]
Derivative Liabilities, Not designated, Fair Value	[1]	(183)	(269)
Derivative Assets [Member]
Derivative [Line Items]
Derivative Assets, Not designated, Fair Value	[1]	16	22
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative notional amount		722	747
Interest Rate Swap [Member] | Derivative Liabilities [Member]
Derivative [Line Items]
Derivative Liabilities, Not designated, Fair Value	[1]	(136)	(193)
Interest Rate Swap [Member] | Other Assets [Member]
Derivative [Line Items]
Derivative Assets, Not designated, Fair Value	[1]	2	2
Credit Default Swap [Member]
Derivative [Line Items]
Derivative notional amount		77	127
Credit Default Swap [Member] | Derivative Liabilities [Member]
Derivative [Line Items]
Derivative Liabilities, Not designated, Fair Value	[1]	(27)	(63)
Insured Swaps [Member]
Derivative [Line Items]
Derivative notional amount		2,561	2,801
Insured Swaps [Member] | Derivative Liabilities [Member]
Derivative [Line Items]
Derivative Liabilities, Not designated, Fair Value	[1]	(2)	(2)
Interest Rate Swaps V I E [Member]
Derivative [Line Items]
Derivative notional amount		0	0
Interest Rate Swaps V I E [Member] | Derivative Liabilities V I E [Member]
Derivative [Line Items]
Derivative Liabilities, Not designated, Fair Value	[1]	0	0
Interest Rate Swaps V I E [Member] | Derivative Assets V I E [Member]
Derivative [Line Items]
Derivative Assets, Not designated, Fair Value		0
Interest Rate Swaps Embedded [Member]
Derivative [Line Items]
Derivative notional amount		296	305
Interest Rate Swaps Embedded [Member] | Medium Term Notes [Member]
Derivative [Line Items]
Derivative Assets, Not designated, Fair Value	[1]	0	1
Derivative Liabilities, Not designated, Fair Value	[1]	(10)	(6)
Currency Swaps Vie [Member]
Derivative [Line Items]
Derivative notional amount		64	69
Currency Swaps Vie [Member] | Other Assets V I E [Member]
Derivative [Line Items]
Derivative Assets, Not designated, Fair Value	[1]	14	19
All Other [Member]
Derivative [Line Items]
Derivative notional amount		49	49
All Other [Member] | Derivative Liabilities [Member]
Derivative [Line Items]
Derivative Liabilities, Not designated, Fair Value	[1]	(8)	(4)
All Other V I E [Member]
Derivative [Line Items]
Derivative notional amount		0	0
All Other V I E [Member] | Other Assets V I E [Member]
Derivative [Line Items]
Derivative Assets, Not designated, Fair Value		0
All Other Embedded [Member]
Derivative [Line Items]
Derivative notional amount		0	2
All Other Embedded [Member] | Derivative Liabilities Other Investments [Member]
Derivative [Line Items]
Derivative Liabilities, Not designated, Fair Value	[1]	0	(1)
Insured Swaps - Held for Sale [Member]
Derivative [Line Items]
Derivative notional amount		$ 0	$ 0
[1]	In accordance with the accounting guidance for derivative instruments and hedging activities, the balance sheet location of the Company's embedded derivative instruments is determined by the location of the related host contract

Derivative Instruments (Effect

Derivative Instruments (Effect Of Derivative Instruments On Consolidated Statements Of Operations) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative [Line Items]
Net gain/(loss) recognized in income	$ 2	$ 0	$ 11	$ (84)
Unrealized Gains Losses On Insured Derivatives [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	4	6	36	(10)
Realized Gains Losses And Other Settlements On Insured Derivatives [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	(5)	(7)	(49)	(41)
Foreign Exchange And Other Derivative Financial Instruments [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	7	(3)	33	(8)
Foreign Exchange And Other Derivative Financial Instruments [Member] | All Other [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	(4)	0	(4)	(19)
Foreign Exchange And Other Derivative Financial Instruments Attributable To V I E [Member] | Interest Rate Swaps V I E [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income		0	0	0
Foreign Exchange And Other Derivative Financial Instruments Attributable To V I E [Member] | Currency Swaps Vie [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	$ 0	$ 4	$ (5)	$ (6)

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Detail) - USD ($) $ in Millions	Jan. 01, 2018	Sep. 30, 2018	Dec. 31, 2017
Non Variable Interest Entities [Line Items]
NOL carryforward		$ 2,500
Alternative minimum tax credit carryforward - Other assets		24
Foreign tax credit		62
Unrecognized Tax Benefits		$ 0	$ 0
New federal corporate tax rate	21.00%

Income Taxes (Income Taxes And

Income Taxes (Income Taxes And Related Effective Tax Rates) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disclosure Income Taxes Income Taxes And Related Effective Tax Rates [Abstract]
Income (loss) before income taxes	$ (45)	$ (273)	$ (287)	$ (603)
Provision (benefit) for income taxes	$ 0	$ (6)	$ 2	$ 965
Effective tax rate	0.00%	2.20%	(0.70%)	(160.00%)

Business Segments (Narrative) (

Business Segments (Narrative) (Detail)	9 Months Ended
	Sep. 30, 2018segments
Disclosure Business Segments Summary Of Companys Segment Results [Abstract]
Number of operating segments	3

Business Segments (Summary Of C

Business Segments (Summary Of Company's Segment Results) (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenues	[1]	$ 110	$ 87	$ 257	$ 277
Net change in fair value of insured derivatives		(1)	(1)	(13)	(51)
Net gains (losses) on financial instruments at fair value and foreign exchange		5	(11)	18	(55)
Net investment losses related to other-than-temporary impairments		(1)	(71)	(3)	(84)
Net gains (losses) on extinguishment of debt		3	1	3	9
Other net realized gains (losses)		1	(1)	0	36
Revenues of consolidated VIEs		(12)	29	(72)	50
Inter-segment revenues	[2]	0	0	0	0
Total revenues		105	33	190	182
Losses and loss adjustment		46	205	177	469
Operating		27	29	74	105
Interest		52	50	155	148
Expenses of consolidated VIEs		25	22	71	63
Inter-segment expenses	[2]	0	0	0	0
Total expenses		150	306	477	785
Income (loss) before income taxes		(45)	(273)	(287)	(603)
Provision (benefit) for income taxes		0	(6)	2	965
Net income (loss)		(45)	(267)	(289)	(1,568)
Identifiable assets		8,361	9,544	8,361	9,544	$ 9,095
Operating Segments [Member] | U S Public Finance Insurance [Member]
Segment Reporting Information [Line Items]
Revenues	[1]	45	70	139	200
Net change in fair value of insured derivatives		0	0	0	0
Net gains (losses) on financial instruments at fair value and foreign exchange		1	2	(13)	20
Net investment losses related to other-than-temporary impairments		(1)	(71)	(3)	(84)
Net gains (losses) on extinguishment of debt		0	0	0	0
Other net realized gains (losses)		0	(1)	0	(1)
Revenues of consolidated VIEs		0	0	0	0
Inter-segment revenues	[2]	7	4	20	14
Total revenues		52	4	143	149
Losses and loss adjustment		48	141	184	310
Operating		5	8	14	34
Interest		0	0	0	0
Expenses of consolidated VIEs		0	0	0	0
Inter-segment expenses	[2]	10	16	34	47
Total expenses		63	165	232	391
Income (loss) before income taxes		(11)	(161)	(89)	(242)
Provision (benefit) for income taxes		(3)	(55)	(20)	(86)
Net income (loss)		(8)	(106)	(69)	(156)
Identifiable assets		4,453	5,051	4,453	5,051
Operating Segments [Member] | Corporate Operations [Member]
Segment Reporting Information [Line Items]
Revenues	[1]	7	7	20	23
Net change in fair value of insured derivatives		0	0	0	0
Net gains (losses) on financial instruments at fair value and foreign exchange		17	(15)	48	(54)
Net investment losses related to other-than-temporary impairments		0	0	0	0
Net gains (losses) on extinguishment of debt		3	1	3	9
Other net realized gains (losses)		0	(1)	(2)	(3)
Revenues of consolidated VIEs		0	0	0	0
Inter-segment revenues	[2]	11	15	36	46
Total revenues		38	7	105	21
Losses and loss adjustment		0	0	0	0
Operating		13	14	39	46
Interest		20	22	60	66
Expenses of consolidated VIEs		0	0	0	0
Inter-segment expenses	[2]	5	0	14	2
Total expenses		38	36	113	114
Income (loss) before income taxes		0	(29)	(8)	(93)
Provision (benefit) for income taxes		2	(1)	(31)	1,069
Net income (loss)		(2)	(28)	23	(1,162)
Identifiable assets		1,062	1,205	1,062	1,205
Operating Segments [Member] | International And Structured Finance Insurance [Member]
Segment Reporting Information [Line Items]
Revenues	[1]	58	10	98	54
Net change in fair value of insured derivatives		(1)	(1)	(13)	(51)
Net gains (losses) on financial instruments at fair value and foreign exchange		(13)	2	(17)	(21)
Net investment losses related to other-than-temporary impairments		0	0	0	0
Net gains (losses) on extinguishment of debt		0	0	0	0
Other net realized gains (losses)		1	1	2	40
Revenues of consolidated VIEs		(12)	29	(72)	50
Inter-segment revenues	[2]	6	11	18	31
Total revenues		39	52	16	103
Losses and loss adjustment		(2)	64	(7)	159
Operating		9	7	21	25
Interest		32	28	95	82
Expenses of consolidated VIEs		25	22	71	63
Inter-segment expenses	[2]	9	14	27	42
Total expenses		73	135	207	371
Income (loss) before income taxes		(34)	(83)	(191)	(268)
Provision (benefit) for income taxes		0	1	(5)	1,143
Net income (loss)		(34)	(84)	(186)	(1,411)
Identifiable assets		5,026	5,320	5,026	5,320
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Inter-segment revenues	[2]	(24)	(30)	(74)	(91)
Total revenues		(24)	(30)	(74)	(91)
Inter-segment expenses	[2]	(24)	(30)	(75)	(91)
Total expenses		(24)	(30)	(75)	(91)
Income (loss) before income taxes		0	0	1	0
Provision (benefit) for income taxes		1	49	58	(1,161)
Net income (loss)		(1)	(49)	(57)	1,161
Identifiable assets	[3]	$ (2,180)	$ (2,032)	$ (2,180)	$ (2,032)
[1]	Represents the sum of third-party financial guarantee net premiums earned, net investment income, insurance-related fees and reimbursements and other fees.
[2]	Represents intercompany premium income and expense and intercompany interest income and expense pertaining to intercompany receivables and payables.
[3]	Consists primarily of intercompany reinsurance balances and repurchase agreements.

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Detail) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Shares [Abstract]
Antidilutive stock options, restricted stock and warrants outstanding	1.4	14.4	1.4	14.4

Earnings Per Share (Computation

Earnings Per Share (Computation Of Basic And Diluted Earnings Per Share) (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Basic earnings per share: [Abstract]
Net income (loss)	$ (45)	$ (267)	$ (289)	$ (1,568)
Net income (loss) available to common stockholders	$ (45)	$ (267)	$ (289)	$ (1,568)
Basic weighted average shares	89,490,267	122,967,924	89,075,892	126,643,642
Basic	$ (0.5)	$ (2.17)	$ (3.24)	$ (12.38)
Diluted earnings per share: [Abstract]
Net income (loss)	$ (45)	$ (267)	$ (289)	$ (1,568)
Net income (loss) available to common stockholders	$ (45)	$ (267)	$ (289)	$ (1,568)
Basic weighted average shares	89,490,267	122,967,924	89,075,892	126,643,642
Diluted weighted average shares	89,490,267	122,967,924	89,075,892	126,643,642
Diluted	$ (0.5)	$ (2.17)	$ (3.24)	$ (12.38)
Unvested Restricted Stock And Units That Receive Nonforfeitable Dividends Or Dividend Equivalents That Have Met Service Condition	900,000	300,000	800,000	300,000

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Changes In The Components Of AOCI) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Beginning balance			$ (19)
Other comprehensive income (loss) before reclassification			(20)
Amounts reclassified from AOCI			0
Total other comprehensive income (loss)	$ 49	$ 54	(20)	$ 143
Ending balance	(206)		(206)
ASU 2018-02 [Member]
Cumulative effect of prospective application of new accounting principle			3
Unrealized gains (losses) on AFS, net [Member]
Beginning balance			(10)
Other comprehensive income (loss) before reclassification			(18)
Amounts reclassified from AOCI			0
Total other comprehensive income (loss)			(18)
Ending balance	(33)		(33)
Unrealized gains (losses) on AFS, net [Member] | ASU 2016-01 [Member]
Cumulative effect of prospective application of new accounting principle			(2)
Unrealized gains (losses) on AFS, net [Member] | ASU 2018-02 [Member]
Cumulative effect of prospective application of new accounting principle			(3)
Foreign currency translation, net [Member]
Beginning balance			(9)
Other comprehensive income (loss) before reclassification			2
Amounts reclassified from AOCI			0
Total other comprehensive income (loss)			2
Ending balance	(7)		(7)
Foreign currency translation, net [Member] | ASU 2016-01 [Member]
Cumulative effect of prospective application of new accounting principle			0
Foreign currency translation, net [Member] | ASU 2018-02 [Member]
Cumulative effect of prospective application of new accounting principle			0
Instrument-specific credit risk of liabilities measured at fair value, net [Member]
Beginning balance			0
Other comprehensive income (loss) before reclassification			(4)
Amounts reclassified from AOCI			0
Total other comprehensive income (loss)			(4)
Ending balance	$ (166)		(166)
Instrument-specific credit risk of liabilities measured at fair value, net [Member] | ASU 2016-01 [Member]
Cumulative effect of prospective application of new accounting principle			(162)
Instrument-specific credit risk of liabilities measured at fair value, net [Member] | ASU 2018-02 [Member]
Cumulative effect of prospective application of new accounting principle			0
Accumulated Other Comprehensive Income [Member]
Total other comprehensive income (loss)			(20)
Accumulated Other Comprehensive Income [Member] | ASU 2016-01 [Member]
Cumulative effect of prospective application of new accounting principle			(164)
Accumulated Other Comprehensive Income [Member] | ASU 2018-02 [Member]
Cumulative effect of prospective application of new accounting principle			$ (3)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Details Of The Reclassification From AOCI) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net gains (losses) on financial instruments at fair value and foreign exchange	$ 5	$ (11)	$ 18	$ (55)
Income (loss) before income taxes	(45)	(273)	(287)	(603)
Provision (benefit) for income taxes	0	(6)	2	965
Net income (loss)	(45)	(267)	(289)	(1,568)
Amounts reclassified from AOCI [Member]
Net income (loss)	0	(5)	0	(1)
Unrealized gains (losses) on AFS, net [Member] | Amounts reclassified from AOCI [Member]
Net gains (losses) on financial instruments at fair value and foreign exchange	2	0	4	6
Other-than-temporary impairments recognized in accumulated other comprehensive income (loss)	(2)	(4)	(3)	(6)
Net investment income	0	(1)	(1)	(2)
Income (loss) before income taxes	0	(5)	0	(2)
Provision (benefit) for income taxes	$ 0	$ 0	$ 0	$ (1)

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Detail) $ in Millions	Sep. 30, 2018USD ($)Lawsuits
Commitments and Contingencies [Abstract]
Other material lawsuits pending | Lawsuits	0
Operating leases future minimum payments due | $	$ 34
Pledged Sales Tax Base Amount [Member]
Loss Contingencies [Line Items]
COFINA and PR Commonwealth settlement percentage	53.65%
Cash Held In Trust BONY Mellon [Member]
Loss Contingencies [Line Items]
COFINA and PR Commonwealth settlement percentage	100.00%