Net Income Per Share - Summary of Table Reconciling Basic and Diluted Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Net income	$ 56,276	$ 47,983
Basic Net Income Per Share, Weighted average common shares outstanding	174,734	151,721
Basic Net Income Per Share	$ 0.32	$ 0.32
Effect of dilutive securities: Restricted stock	582	569
Effect of dilutive securities: Stock options	52	80
Diluted Net Income Per Share, Weighted average shares outstanding	175,368	152,370
Diluted Net Income Per Share	$ 0.32	$ 0.31