Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Major Jurisdictions

The following are the major jurisdictions in which Ambac and its subsidiaries operate and the earliest tax years subject to examination:

Jurisdiction	Tax Year
United States	2010
New York State	2013
New York City	2014
United Kingdom	2014
Italy	2013

Significant Portions of Deferred Tax Liabilities and Deferred Tax Assets

The tax effects of temporary differences that give rise to significant portions of the deferred tax liabilities and deferred tax assets at December 31, 2017 and 2016 are presented below:

December 31,	2017			2016
Deferred tax liabilities:
Insurance intangible	$	177,864		$	336,728
Variable interest entities	22,817			46,343
Investments	28,798			38,656
Unearned premiums and credit fees	51,485			68,682
Unremitted foreign earnings	—			30,699
Other	9,402			4,276
Total deferred tax liabilities	290,366			525,384
Deferred tax assets:
Net operating loss and capital carryforward	775,917			1,409,565
Loss reserves	236,237			224,553
Compensation	5,585			4,759
AMT Credits	—			31,532
Other	2,140			11,967
Subtotal deferred tax assets	1,019,879			1,682,376
Valuation allowance	763,172			1,158,712
Total deferred tax assets	256,707			523,664
Net deferred tax (liability)	(33,659		)	(1,720		)

Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]

U.S. and foreign components of pre-tax income (loss) were as follows:

Year Ended December 31,	2017			2016		2015
U.S.	$	(450,978	)	$	77,161	$	337,753
Foreign	166,727			27,865		172,305
Total	$	(284,251	)	$	105,026	$	510,058

Schedule of Components of Income Tax Expense (Benefit)

The components of the provision (benefit) for income taxes were as follows:

Year Ended December 31,	2017			2016			2015
Current taxes
U. S. federal	$	(29,581	)	$	3,934		$	16,893
U.S. state and local	2,013			707			182
Foreign	40,613			26,088			2
Current taxes	13,045			30,729			17,077
Deferred taxes
Deferred taxes - foreign	31,419			(20		)	287
Provision for income taxes	$	44,464		$	30,709		$	17,364

Schedule Of Income Taxes Charged Credited Directly To Equity

The total effect of income taxes on net income and stockholders’ equity for the years ended December 31, 2017, 2016 and 2015 is as follows:

Year Ended December 31,	2017			2016			2015
Total income taxes charged to net income	$	44,464		$	30,709		$	17,364
Income taxes charged (credited) to stockholders’ equity:
Unrealized gains (losses) on investment securities	(30,838		)	41,602			(55,906		)
Unrealized gains (losses) on foreign currency translations	25,776			(58,527		)	(15,628		)
Change in retirement benefits	446			3,278			(240		)
Valuation allowance to equity	4,616			13,647			71,774
Total effect of income taxes	$	44,464		$	30,709		$	17,364

Schedule of Effective Income Tax Rate Reconciliation

The tax provisions in the accompanying Consolidated Statements of Total Comprehensive Loss reflect effective tax rates differing from prevailing Federal corporate income tax rates. The following is a reconciliation of these differences:

	2017					2016					2015
Year Ended December 31,	Amount			%		Amount			%		Amount			%
Tax on income from continuing operations at statutory rate	$	(99,488	)	35.0	%	$	36,759		35.0	%	$	178,521		35.0	%
Changes in expected tax resulting from:
Tax-exempt interest	(6,004		)	2.1	%	(1,561		)	(1.5	)%	(1,454		)	(0.3	)%
Goodwill impairment	—			—	%	—			—	%	180,079			35.3	%
Foreign taxes	(17,742		)	6.2	%	26,183			24.9	%	288			0.1	%
Substantiation adjustment	36,124			(12.7	)%	(171,687		)	(163.5	)%	—			—	%
Valuation allowance	127,675			(44.9	)%	139,584			132.9	%	(340,133		)	(66.7	)%
Change in Tax Law	1,886			(0.7	)%	—			—	%	—			—	%
Other, net	2,013			(0.7	)%	1,431			1.4	%	63			—	%
Tax expense on income from continuing operations	$	44,464		(15.6	)%	$	30,709		29.2	%	$	17,364		3.4	%

Schedule of Unrecognized Tax Benefits Roll Forward

A reconciliation of the beginning and ending amount of unrecognized tax benefits for 2017, 2016 and 2015 is as follows:

Year Ended December 31,	2017		2016		2015
Balance, beginning of period	$	—	$	—	$	—
Increases related to prior year tax positions	—		—		—
Decreases related to prior year tax positions	—		—		—
Balance, end of period	$	—	$	—	$	—

Schedule of Net Operating Loss And Tax Credit Carryovers

Pursuant to the amended and restated tax sharing agreement among Ambac, Ambac Assurance and certain affiliates (the “Amended TSA"), to the extent Ambac Assurance generates taxable income after September 30, 2011, which is offset with "Allocated NOLs" of $3,650,000, it is obligated to make payments (“Tolling Payments”), subject to certain credits, to Ambac in accordance with the following NOL usage table, where the “Applicable Percentage” is applied to the aggregate amount of federal income tax liability that would have been paid if the Allocated NOLs were not available. Pursuant to the Closing Agreement between Ambac and the Internal Revenue Service ("IRS"), the IRS will receive 12.5% of Tier C and 17.5% of Tier D payments, if made.

NOL Usage Table

NOL Usage Tier	Allocated NOLs			Applicable Percentage
A	The first	$479,000		15%
B	The next	$1,057,000	after Tier A	40%
C	The next	$1,057,000	after Tier B	10%
D	The next	$1,057,000	after Tier C	15%