Earnings Per Share (Details) - USD ($) $ in Thousands		3 Months Ended					9 Months Ended
		Sep. 30, 2021	Jun. 30, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Class of Stock [Line Items]
Share repurchased (shares)		4,293,924					4,293,924
Shares repurchased		$ 46,200					$ 46,200
Shares repurchased and retired (shares)				0				3,328,574
Shares repurchased and retired					$ 25	$ 46		$ 30,100
Shares repurchased pending settlement (shares)		363,616					363,616
Shares repurchased pending settlement		$ 3,900					$ 3,900
Participating securities (shares)		136,324		77,157			123,343	65,264
Anti-dilutive shares (shares)		1,372,601		1,730,960			1,461,000	1,644,002
Weighted average common shares outstanding for basic calculation (shares)		267,106,109		267,265,705			267,327,888	267,908,427
Add: Effect of stock options, deferred stock units and restricted stock units (shares)		72,854		13,850			113,506	12,463
Weighted average common shares outstanding for diluted calculation (shares)		267,178,963		267,279,555			267,441,394	267,920,890
Participating securities (shares)		136,324		77,157			123,343	65,264
Anti-dilutive shares (shares)		1,372,601		1,730,960			1,461,000	1,644,002
Common Stock
Class of Stock [Line Items]
Share repurchased (shares)	[1]	4,293,924
Shares repurchased	[1]	$ 43
Shares repurchased and retired (shares)			294,250
Shares repurchased and retired			$ 3

[1] *In the third quarter 2021, stock repurchases of 363,616 shares totaling $3.9 million were pending settlement as of September 30, 2021. This is included in "Accounts payable" on the Condensed Consolidated Balance Sheet. See Note 11 "Earnings per Share" for details.