Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income (loss)	$ (118,401)	$ (55,470)	$ 251,114	$ (98,065)
Weighted average common shares outstanding:
Basic (in shares)	183,178	186,140	183,682	186,442
Effect of dilutive securities - Unvested restricted stock and restricted stock units	$ 0	$ 0	$ 180	$ 0
Diluted (in shares)	183,178	186,140	183,862	186,442
Earnings Per Share, Basic and Diluted [Abstract]
Basic (in dollars per share)	$ (0.65)	$ (0.30)	$ 1.37	$ (0.53)
Diluted (in dollars per share)	$ (0.65)	$ (0.30)	$ 1.37	$ (0.53)
Performance-Based Restricted Shares
Weighted average common shares outstanding:
Diluted (in shares)	1,800
Unvested Restricted Stock
Weighted average common shares outstanding:
Diluted (in shares)	9,100		7,100
Earnings Per Share, Basic and Diluted [Abstract]
Antidilutive securities (shares)		7,800		7,500