Consolidated Statements Of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Loss
Balance, beginning of year at Dec. 31, 2017	$ 1,567,393	$ 1,284,274	$ 352,906	$ (69,787)
Balance, beginning of year (in shares) at Dec. 31, 2017		147,740
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	28,598		28,598
Reclassification of stranded tax effect to retained earnings			1,530	(1,530)
Foreign currency translation adjustments	(7,166)			(7,166)
Unrealized gain on hedges, net of tax	5,016			5,016
Accretion of redeemable noncontrolling interests	0
Unrealized loss on note receivable, net of tax	(497)			(497)
Equity component of debt discount on convertible senior notes	15,411	$ 15,411
Activity in company stock plans, net and other	(746)	$ (746)
Activity in company stock plans, net and other (in shares)		463
Share-based compensation	9,770	$ 9,770
Balance, end of year at Dec. 31, 2018	1,617,779	$ 1,308,709	383,034	(73,964)
Balance, end of year (in shares) at Dec. 31, 2018		148,203
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	57,919		57,919
Reclassification of deferred gain from sale leaseback transaction to retained earnings	4,560		4,560
Foreign currency translation adjustments	5,400			5,400
Unrealized gain on hedges, net of tax	3,824			3,824
Accretion of redeemable noncontrolling interests	(143)		(143)
Unrealized loss on note receivable, net of tax	0
Activity in company stock plans, net and other	(1,032)	$ (1,032)
Activity in company stock plans, net and other (in shares)		685
Share-based compensation	11,284	$ 11,284
Balance, end of year at Dec. 31, 2019	1,699,591	$ 1,318,961	445,370	(64,740)
Balance, end of year (in shares) at Dec. 31, 2019		148,888
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	22,174		22,174
Credit losses recognized in retained earnings upon adoption of ASU No. 2016-13	(620)		(620)
Foreign currency translation adjustments	12,835			12,835
Unrealized gain on hedges, net of tax	285			285
Accretion of redeemable noncontrolling interests	(2,400)		(2,400)
Unrealized loss on note receivable, net of tax	0
Equity component of debt discount on convertible senior notes	33,336	$ 33,336
Re-acquisition of equity component of convertible senior notes	(18,006)	(18,006)
Capped call transactions	(10,625)	(10,625)
Activity in company stock plans, net and other	(4,345)	$ (4,345)
Activity in company stock plans, net and other (in shares)		1,453
Share-based compensation	8,271	$ 8,271
Balance, end of year at Dec. 31, 2020	$ 1,740,496	$ 1,327,592	$ 464,524	$ (51,620)
Balance, end of year (in shares) at Dec. 31, 2020		150,341