Consolidated Statements of Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Successor [Member]	Successor [Member] Retained Earnings/Accumulated Deficit [Member]	Successor [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Successor [Member] Preferred Stock [Member]	Successor [Member] Common Stock [Member]	Successor [Member] Additional Paid-in Capital [Member]	Successor [Member] Common Stock Held in Treasury, at Cost [Member]	Successor [Member] Noncontrolling Interest [Member]	Predecessor [Member]	Predecessor [Member] Retained Earnings/Accumulated Deficit [Member]	Predecessor [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Predecessor [Member] Preferred Stock [Member]	Predecessor [Member] Common Stock [Member]	Predecessor [Member] Additional Paid-in Capital [Member]	Predecessor [Member] Common Stock Held in Treasury, at Cost [Member]	Predecessor [Member] Noncontrolling Interest [Member]
Beginning balance at Dec. 31, 2011									$ (3,149,533)	$ (6,039,922)	$ 463,259	$ 0	$ 3,080	$ 2,172,027	$ (411,419)	$ 663,442
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income									(97,434)	(256,678)	162,126	0	0	0	0	(2,882)
Stock-based compensation									(664)	(664)	0	0	0	0	0	0
Cost of shares acquired									664	0	0	0	0	0	664	0
Ending balance at Dec. 31, 2012									(3,246,967)	(6,297,264)	625,385	0	3,080	2,172,027	(410,755)	660,560
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income									3,522,382	3,349,049	174,875	0	0	0	0	(1,542)
Stock-based compensation									(60)	(60)	0	0	0	0	0	0
Cost of shares acquired									60	0	0	0	0	0	60	0
Elimination of Predecessor Ambac Shareholder equity accounts and noncontrolling interest adjustment									0	2,948,275	(800,260)	0	(3,080)	(2,172,027)	410,695	(383,603)
Ending balance at Apr. 30, 2013	460,415	0	0	0	450	184,550	0	275,415	275,415	0	0	0	0	0	0	275,415
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income	516,904	505,219	11,661	0	0	0	0	24
Stock-based compensation	1,106	0	0	0	0	1,106	0	0
Warrants exercised	16	0	0	0	0	16	0	0
Cost of shares acquired	(19)	0	0	0	0	0	(19)	0
Ending balance at Dec. 31, 2013	978,422	505,219	11,661	0	450	185,672	(19)	275,439
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income	691,884	484,071	208,622	0	0	0	0	(809)
Stock-based compensation	3,450	0	0	0	0	3,450	0	0
Cost of shares acquired	(37)	0	0	0	0	0	(37)	0
Warrants exercised	16	0	0	0	0	16	0	0
Ending balance at Dec. 31, 2014	$ 1,673,735	$ 989,290	$ 220,283	$ 0	$ 450	$ 189,138	$ (56)	$ 274,630