Earnings Per Share (Details) - $ / shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Reconciliation of Weighted-Average Diluted Shares Outstanding
Weighted Average Number of Shares Outstanding, Basic	98,183	99,617	99,018	97,762
Weighted Average Number of Shares Outstanding, Diluted	99,966	99,617	100,534	97,762
Anti-dilutive Effect
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	103	2,054	168	1,946
Convertible Senior Note
Convertible Note, Shares To Be Received Upon Conversion (in thousands)			2,300
Restricted stock
Reconciliation of Weighted-Average Diluted Shares Outstanding
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	1,777	0	1,505	0
Anti-dilutive Effect
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	6	1,831	37	1,715
Stock Appreciation Rights (SARs)
Reconciliation of Weighted-Average Diluted Shares Outstanding
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	6	0	11	0
Anti-dilutive Effect
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	97	223	131	231
1.125% Convertible Senior Notes due 2021 [Member]
Convertible Senior Note
Convertible Note, Conversion Price	$ 85.39		$ 85.39