Income Taxes - Provision for Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended								9 Months Ended	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current:
Federal									$ 0	$ 558	$ 0
State									9	46	10
Total									9	604	10
Deferred:
Federal									0	(67,724)	0
State									0	(22,327)	0
Total									0	(90,051)	0
Income tax expense (benefit)	$ 3,103	$ 10,394	$ (102,976)	$ 32	$ 0	$ 0	$ 10	$ 0	$ 9	$ (89,447)	$ 10	$ 9