Net Income Per Share - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2013	Apr. 30, 2013
Schedule Of Earnings Per Share [Line Items]
Number of new common stock issued	45,004,410	45,004,410	45,003,461
Par value of common stock issued	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Number of shares exercisable for warrants				5,047,138
Exercise price of common stock				16.67
Expiry date of warrants		Apr. 30, 2023
Warrant exercised	898	949
Common stock shares issued		949
Successor Ambac [Member]
Schedule Of Earnings Per Share [Line Items]
Number of new common stock issued				45,000,000
Number of warrants issued				5,047,138
Warrants outstanding	5,039,877	5,039,877