Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended					9 Months Ended
	Sep. 30, 2021		Jun. 30, 2021	Sep. 30, 2020		Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Net earnings from continuing operations	$ 139,996			$ 45,503		$ 470,914	$ (1,354,404)
Less: Earnings allocated to unvested restricted stock	(2,417)	[1]		(578)	[1]	(7,930)	(1,603)
Net earnings allocated to common shares	$ 137,579			$ 44,925		$ 462,984	$ (1,356,007)
Weighted-average basic shares and unvested restricted stock outstanding (shares)	119,569			118,438		119,272	118,469
Weighted-average unvested restricted stock outstanding (shares)	(2,340)			(1,684)		(2,235)	(1,596)
Weighted-average basic shares outstanding (shares)	117,229			116,754		117,037	116,873
Basic net income per share (usd per share)	$ 1.17		$ 1.52	$ 0.38		$ 3.96	$ (11.60)
Net earnings from continuing operations allocated to common shares	$ 137,579			$ 44,925		$ 462,984	$ (1,356,007)
Diluted net income per share (usd per share)	$ 1.17		$ 1.52	$ 0.38		$ 3.96	$ (11.60)

[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.