Consolidated Statements of Total Comprehensive Income - Successor [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenues:
Net premiums earned	$ 41,402	$ 60,879	$ 94,202	$ 126,597
Net investment income:
Securities available-for-sale and short-term	64,368	62,278	122,350	125,610
Other investments	6,390	2,475	9,229	12,126
Total net investment income	70,758	64,753	131,579	137,736
Other-than-temporary impairment losses:
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	18,880	1,391	66,950	11,752
Portion of other-than-temporary impairment recognized in other comprehensive income	11,439	371	50,175	7,613
Net other-than-temporary impairments	(7,441)	(1,020)	(16,775)	(4,139)
Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments	14,897	(5,353)	15,999	48,748
Change in fair value of credit derivatives:
Gain (Loss) on Sale of Derivatives	233	407	485	826
Unrealized gains (losses)	3,722	9,886	16,336	6,968
Net change in fair value of credit derivatives	3,955	10,293	16,821	7,794
Derivative products	(36,331)	50,999	(119,755)	13,225
Net realized gains (losses) on extinguishment of debt	3,586	(1,246)	4,821	(1,339)
Other Operating Income (Expense), Net	6,919	(1,156)	14,918	(1,944)
Income (loss) on variable interest entities	8,987	52,603	(18,176)	59,565
Total revenues	106,732	230,752	123,634	386,243
Expenses:
Losses and loss expense (benefit)	(52,496)	(147,477)	(157,777)	(298,429)
Insurance intangible amortization	39,013	38,088	89,903	75,520
Operating expenses	27,995	25,873	56,004	50,396
Interest expense	30,709	28,173	61,139	56,081
Total expenses (benefit)	45,221	(55,343)	49,269	(116,432)
Pre-tax income	61,511	286,095	74,365	502,675
Provision for income taxes	3,156	3,917	6,595	5,626
Net income	58,355	282,178	67,770	497,049
Less: net (gain) loss attributable to noncontrolling interest	(292)	(517)	(292)	(357)
Net income attributable to common stockholders	58,647	282,695	68,062	497,406
Other comprehensive income, after tax:
Net income	58,355	282,178	67,770	497,049
Unrealized gains (losses) on securities, net of deferred income taxes of $0	48,170	(113,839)	107,961	(131,287)
Gains (losses) on foreign currency translation, net of deferred income taxes of $0	(55,152)	40,490	(72,933)	6,685
Changes to postretirement benefit, net of tax of $0	(255)	(220)	532	(247)
Total other comprehensive income (loss), net of tax	(7,237)	(73,569)	35,560	(124,849)
Total comprehensive income	51,118	208,609	103,330	372,200
Less: comprehensive (loss) gain attributable to the noncontrolling interest:
Net (gain) loss	(292)	(517)	(292)	(357)
Currency translation adjustments	0	398	0	72
Total comprehensive income attributable to Ambac Financial Group, Inc.	$ 51,410	$ 208,728	$ 103,622	$ 372,485
Earnings Per Share, Basic	$ 1.30	$ 6.26	$ 1.51	$ 11.01
Earnings Per Share, Diluted	$ 1.29	$ 6.05	$ 1.50	$ 10.62