Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Balance at Dec. 31, 2019	$ 891,957	$ 442	$ 280,216	$ 645,507	$ (24,829)	$ (9,379)
Balance (in shares) at Dec. 31, 2019		44,209
Increase (Decrease) in Stockholders' Equity
Net income	36,826			36,826
Translation adjustment	(7,593)				(7,593)
Pension adjustment, net of tax	273				273
Unrealized gains on derivative instruments	0
Stock-based compensation	33		33
Shares issued from release of Restricted Stock Units	(7,697)	$ 2	(7,699)
Shares issued from release of Restricted Stock Units (in shares)		153
Repurchase of common stock	(62,679)					(62,679)
Repurchase of common stock (in shares)		(902)
Cash dividends declared on common stock	(9,848)			(9,848)
Common stock issued	322		322
Common stock issued (in shares)		4
Balance at Mar. 31, 2020	841,594	$ 444	272,872	672,485	(32,149)	(72,058)
Balance (in shares) at Mar. 31, 2020		43,464
Balance at Dec. 31, 2020	980,943	$ 433	284,007	720,441	(10,428)	(13,510)
Balance (in shares) at Dec. 31, 2020		43,326
Increase (Decrease) in Stockholders' Equity
Net income	50,387			50,387
Translation adjustment	(9,264)				(9,264)
Pension adjustment, net of tax	492				492
Unrealized gains on derivative instruments	26				26
Stock-based compensation	6,462		6,462
Shares issued from release of Restricted Stock Units	(5,263)	$ 1	(5,264)
Shares issued from release of Restricted Stock Units (in shares)		97
Cash dividends declared on common stock	(9,966)			(9,966)
Common stock issued	692	$ 1	691
Common stock issued (in shares)		7
Balance at Mar. 31, 2021	$ 1,014,509	$ 435	$ 285,896	$ 760,862	$ (19,174)	$ (13,510)
Balance (in shares) at Mar. 31, 2021		43,430