Earnings (Loss) per Common Share - Earnings per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Basic Earnings:
Net income (loss) available to common stockholders, basic	$ 96,859	$ 77,896	$ (1,830,385)	$ 212,809
Basic Earnings:
Shares available to common stockholders (in shares)	181,350,000	135,799,000	168,402,000	128,574,000
Effect of dilutive securities:
Restricted stock awards (in shares)	11,000	13,000	0	12,000
Dilutive Shares (in shares)	181,361,000	135,812,000	168,402,000	128,586,000
Net income (loss) attributable to common stockholders
Basic (usd per share)	$ 0.53	$ 0.57	$ (10.87)	$ 1.66
Diluted (usd per share)	$ 0.53	$ 0.57	$ (10.87)	$ 1.65
Restricted stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of EPS (in shares)			11,131