Condensed Consolidated Statements Of Equity Condensed Consolidatd Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Treasury Stock, Common	Additional Paid-in Capital	Retained Earnings	Foreign currency translation adjustments	Defined benefit pension adjustments
Balance (in shares) at Dec. 31, 2018		136,179	(202)
Balance at Dec. 31, 2018	$ 1,012,025	$ 1,362	$ (7,112)	$ 837,658	$ 213,753	$ (32,776)	$ (860)
Shares issued under stock plans (in shares)		572
Shares issued under stock plans	(6,812)	$ 5	0	(6,817)	0	0	0
Share-based compensation expense	4,653	$ 0	0	4,653	0	0	0
Repurchase and retirements of common stock (in shares)		(1,035)
Repurchase and retirements of common stock	(29,787)	$ (10)	0	(6,364)	(23,413)	0	0
Dividends declared	(9,510)	0	0		(9,517)	0	0
Dividends declared				7
Pension liability adjustments	24	0	0	0	0	0	24
Foreign currency translation adjustments	(2,787)	0	0	0	0	(2,787)	0
Net income	32,658	$ 0	$ 0	0	32,658	0	0
Balance (in shares) at Mar. 30, 2019		135,716	(202)
Balance at Mar. 30, 2019	1,000,464	$ 1,357	$ (7,112)	829,137	213,481	(35,563)	(836)
Balance (in shares) at Dec. 31, 2019		134,930	(202)
Balance at Dec. 31, 2019	1,165,889	$ 1,349	$ (7,112)	842,784	366,127	(36,468)	(791)
Shares issued under stock plans (in shares)		483
Shares issued under stock plans	(10,889)	$ 5	0	(10,894)	0	0	0
Share-based compensation expense	4,994	$ 0	0	4,994	0	0	0
Repurchase and retirements of common stock (in shares)		(604)
Repurchase and retirements of common stock	(29,564)	$ (6)	0	(3,740)	(25,818)	0	0
Dividends declared	(10,758)	0	0		(10,773)	0	0
Dividends declared				15
Pension liability adjustments	10	0	0	0	0	0	10
Foreign currency translation adjustments	(9,361)	0	0	0	0	(9,361)	0
Net income	61,006	$ 0	$ 0	0	61,006	0	0
Balance (in shares) at Mar. 28, 2020		134,809	(202)
Balance at Mar. 28, 2020	$ 1,171,327	$ 1,348	$ (7,112)	$ 833,159	$ 390,542	$ (45,829)	$ (781)