Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Numerator:
Net income	$ 18,588	$ 5,995
Less: income allocable to participating securities	(232)
Income allocable to common shares	18,356	5,995
Add back: undistributed earnings allocable to participating securities	232
Less: undistributed earnings reallocated to participating securities	(227)
Numerator for diluted earnings per share	$ 18,361	$ 5,995
Denominator:
Weighted average common shares outstanding	50,315,455	50,315,455
Adjustment for vested restricted stock	6,817,454	4,434,496
Shares for calculating basic earnings per share	57,132,909	54,749,951
Dilutive effect of unvested restricted stock	1,229,131	1,812,710
Shares for calculating diluted earnings per share	58,362,040	56,562,661
Earnings per share:
Basic	$ 0.32	$ 0.11
Diluted	$ 0.31	$ 0.11