Earnings (Loss) Per Share - Schedule of Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Basic:
Net income (loss), basic	$ (2,626)	$ 26,847
Net income (loss), shares, basic	293,450	261,105
Net income (loss), per share, basic	$ (0.01)	$ 0.10
Weighted-average number of shares of common stock-diluted:
Restricted stock and performance unit awards		3,110
Diluted:
Net income (loss), diluted	$ (2,626)	$ 26,847
Net income (loss), shares, diluted	293,450	264,215
Net income (loss), per share, diluted	$ (0.01)	$ 0.10