Consolidated Statements of Total Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	2 Months Ended	3 Months Ended	6 Months Ended	1 Months Ended	4 Months Ended
	Jun. 30, 2013 Successor Ambac [Member]	Jun. 30, 2014 Successor Ambac [Member]	Jun. 30, 2014 Successor Ambac [Member]	Apr. 30, 2013 Predecessor Ambac [Member]	Apr. 30, 2013 Predecessor Ambac [Member]
Revenues:
Net premiums earned	$ 58,039	$ 65,013	$ 147,560	$ 29,744	$ 130,000
Net investment income:
Securities available-for-sale and short-term	29,211	76,882	145,689	31,314	116,371
Other investments	(3,015)	3,211	5,205	912	369
Total net investment income	26,196	80,093	150,894	32,226	116,740
Other-than-temporary impairment losses:
Total other-than-temporary impairment losses	(2,004)	(9,051)	(19,443)	(467)	(467)
Portion of loss recognized in other comprehensive income	2	297	297	0	0
Net other-than-temporary impairment losses recognized in earnings	(2,002)	(8,754)	(19,146)	(467)	(467)
Net realized investment gains (losses)	18,472	3,067	19,356	7,245	53,305
Change in fair value of credit derivatives:
Realized gains (losses) and other settlements	6,074	717	1,492	935	3,444
Unrealized (losses) gains	45,146	(1,936)	4,671	(74,106)	(63,828)
Net change in fair value of credit derivatives	51,220	(1,219)	6,163	(73,171)	(60,384)
Derivative products	83,713	(47,985)	(101,826)	(33,166)	(33,735)
Other income	2,179	5,266	7,160	(1,135)	8,363
Income (loss) on variable interest entities	4,598	(38,148)	(43,690)	388,240	426,566
Total revenues before expenses and reorganization items	242,415	57,333	166,471	349,516	640,388
Expenses:
Losses and loss expenses (benefit)	(26,117)	175,317	35,306	13,079	(38,056)
Insurance intangible amortization	24,952	36,256	67,970	0	0
Underwriting and operating expenses	16,217	24,033	49,819	10,692	44,566
Interest expense	21,144	31,953	64,281	7,860	31,025
Total expenses before reorganization items	36,196	267,559	217,376	31,631	37,535
Pre-tax (loss) income from continuing operations before reorganization items	206,219	(210,226)	(50,905)	317,885	602,853
Reorganization items	424	186	209	(2,747,239)	(2,745,180)
Pre-tax (loss) income from continuing operations	205,795	(210,412)	(51,114)	3,065,124	3,348,033
(Benefit) provision for income taxes	513	(2,179)	1,070	98	755
Net income (loss)	205,282	(208,233)	(52,184)	3,065,026	3,347,278
Less: net (loss) gain attributable to noncontrolling interest	(399)	(328)	(221)	(1,724)	(1,771)
Net (loss) income attributable to common shareholders	205,681	(207,905)	(51,963)	3,066,750	3,349,049
Other comprehensive (loss) income, after tax:
Net income (loss)	205,282	(208,233)	(52,184)	3,065,026	3,347,278
Unrealized gain (loss) on securities, net of deferred income taxes of $0	(90,983)	185,163	273,885	81,249	175,347
Gain (loss) on foreign currency translation, net of deferred income taxes of $0	(12,662)	17,144	21,428	(167)	(428)
Changes to postretirement benefit, net of tax of $0	0	(204)	(408)	(623)	185
Total other comprehensive income, net of tax	(103,645)	202,103	294,905	80,459	175,104
Total comprehensive income (loss)	101,637	(6,130)	242,721	3,145,485	3,522,382
Less: comprehensive (loss) gain attributable to the noncontrolling interest:
Noncontrolling interest in subsidiaries’ earnings	(399)	(328)	(221)	(1,724)	(1,771)
Currency translation adjustments	(138)	192	238	270	229
Total comprehensive income (loss) attributable to Ambac Financial Group, Inc.	$ 102,174	$ (5,994)	$ 242,704	$ 3,146,939	$ 3,523,924
Net income (loss) per share attributable to Ambac Financial Group, Inc. common shareholders (in dollars per share)	$ 4.57	$ (4.61)	$ (1.15)	$ 10.14	$ 11.07
Net income (loss) per diluted share attributable to Ambac Financial Group, Inc. common shareholders (in dollars per share)	$ 4.42	$ (4.61)	$ (1.15)	$ 10.14	$ 11.07