Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended					6 Months Ended
	Jun. 30, 2021		Mar. 31, 2021	Jun. 30, 2020		Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Net earnings from continuing operations	$ 180,512			$ 33,204		$ 330,918	$ (1,399,907)
Less: Earnings allocated to unvested restricted stock	(3,172)	[1]		(362)	[1]	(5,495)	(1,251)
Net earnings allocated to common shares	$ 177,340			$ 32,842		$ 325,423	$ (1,401,158)
Weighted-average basic shares and unvested restricted stock outstanding (shares)	119,386			118,192		119,121	118,484
Weighted-average unvested restricted stock outstanding (shares)	(2,356)			(1,606)		(2,181)	(1,551)
Weighted-average basic shares outstanding (shares)	117,030			116,586		116,940	116,933
Basic net income per share (usd per share)	$ 1.52		$ 1.27	$ 0.28		$ 2.78	$ (11.98)
Net earnings from continuing operations allocated to common shares	$ 177,340			$ 32,842		$ 325,423	$ (1,401,158)
Diluted net income per share (usd per share)	$ 1.52		$ 1.27	$ 0.28		$ 2.78	$ (11.98)

[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.