Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Earnings Per Share [Abstract]
Net earnings from continuing operations		$ 150,406		$ (1,433,111)
Less: Earnings allocated to unvested restricted stock	[1]	(2,355)		(939)
Net earnings allocated to common shares		$ 148,051		$ (1,434,050)
Weighted-average basic shares and unvested restricted stock outstanding (shares)		118,852		118,775
Weighted-average unvested restricted stock outstanding (shares)		(2,003)		(1,495)
Weighted-average basic shares outstanding (shares)		116,849		117,280
Basic net income per share (usd per share)		$ 1.27	$ 0.99	$ (12.23)
Net earnings from continuing operations allocated to common shares		$ 148,051		$ (1,434,050)
Diluted net income per share (usd per share)		$ 1.27	$ 0.99	$ (12.23)

[1] Represents cash dividends paid to holders of unvested restricted stock, net of forfeitures, plus undistributed earnings amounts available to holders of unvested restricted stock, if any.