Summary of Significant Accounting Policies - Calculation of Basic and Diluted Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Net income (loss)	$ (134,830)	$ 121,220	$ (138,225)
Basic weighted-average common shares outstanding in period (in shares)	210,391,669	188,299,074	76,858,815
Add dilutive effects of stock options and nonvested equity shares of common stock (in shares)	0	942,000	0
Diluted weighted-average common shares outstanding in period (in shares)	210,391,669	189,241,036	76,858,815
Basic net income (loss) per common share (in dollars per share)	$ (0.64)	$ 0.64	$ (1.80)
Diluted net income (loss) per common share (in dollars per share)	$ (0.64)	$ 0.64	$ (1.80)