Earnings Per Common Share - Reconciliation of Weighted-Average Common Shares Outstanding Used in Calculation of Basic EPS to Diluted EPS (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Numerator:
Net income (loss)	$ 5,502	$ 2,038	$ 10,034
Less: Net income allocated to participating securities	(78)	(36)
Numerator for basic and diluted earnings (loss) available to common stockholders	$ 5,424	$ 2,002
Denominator:
Weighted-average basic common shares outstanding (in shares)	48,101	31,317
Weighted-average diluted common shares outstanding (in shares)	48,101	31,317
Earnings (loss) per common share, basic (in usd per share)	$ 0.11	$ 0.06
Earnings (loss) per common share, diluted (in usd per share)	$ 0.11	$ 0.06