Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Earnings Per Share [Abstract]
Net earnings from continuing operations		$ (1,433,111)	$ 117,881	$ 112,604
Less: Earnings allocated to unvested restricted stock	[1]	(939)	(1,458)	(1,163)
Net earnings allocated to common shares		$ (1,434,050)	$ 116,423	$ 111,441
Weighted-average basic shares and unvested restricted stock outstanding (shares)		118,775	119,804	122,227
Weighted-average unvested restricted stock outstanding (shares)		(1,495)	(1,566)	(1,352)
Weighted-average basic shares outstanding (shares)		117,280	118,238	120,875
Basic net income per share (usd per share)		$ (12.23)	$ 0.98	$ 0.92
Net earnings from continuing operations allocated to common shares		$ (1,434,050)	$ 116,423	$ 111,441
Diluted net income per share (usd per share)		$ (12.23)	$ 0.98	$ 0.92

[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.