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, 2018	$ 855,514	$ 453	$ 276,504	$ 628,207	$ (24,650)	$ (25,000)
Balance (in shares) at Dec. 31, 2018		44,998
Increase (Decrease) in Stockholders' Equity
Net income	105,925			105,925
Translation adjustment, net of tax	5,825				(5,825)
Pension adjustment, net of tax	462				462
Stock-based compensation	8,007		8,007
Shares issued from release of Restricted Stock Units	(5,903)	$ 2	(5,905)
Shares issued from release of Restricted Stock Units (in shares)		178
Repurchase of common stock	(51,437)					(51,437)
Repurchase of common stock (in shares)		(854)
Retirement of common stock	0	$ (9)		(54,991)		55,000
Cash dividends declared on common stock	(30,088)			(30,088)
Common stock issued	292		292
Common stock issued (in shares)		5
Balance at Sep. 30, 2019	876,947	$ 446	278,898	649,053	(30,013)	(21,437)
Balance (in shares) at Sep. 30, 2019		44,327
Balance at Jun. 30, 2019	868,421	$ 446	277,024	615,529	(24,578)	0
Balance (in shares) at Jun. 30, 2019		44,675
Increase (Decrease) in Stockholders' Equity
Net income	43,686			43,686
Translation adjustment, net of tax	5,797				(5,797)
Pension adjustment, net of tax	362				362
Stock-based compensation	1,880		1,880
Shares issued from release of Restricted Stock Units	(6)		(6)
Shares issued from release of Restricted Stock Units (in shares)		1
Repurchase of common stock	(21,437)					(21,437)
Repurchase of common stock (in shares)		(349)
Cash dividends declared on common stock	(10,162)			10,162
Balance at Sep. 30, 2019	876,947	$ 446	278,898	649,053	(30,013)	(21,437)
Balance (in shares) at Sep. 30, 2019		44,327
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	157,362			157,362
Translation adjustment, net of tax	3,170				3,170
Pension adjustment, net of tax	88				88
Stock-based compensation	8,481		8,481
Shares issued from release of Restricted Stock Units	(7,903)	$ 2	(7,905)
Shares issued from release of Restricted Stock Units (in shares)		165
Repurchase of common stock	(62,679)					(62,679)
Repurchase of common stock (in shares)		(902)
Cash dividends declared on common stock	(30,018)			(30,018)
Common stock issued	342		342
Common stock issued (in shares)		4
Balance at Sep. 30, 2020	960,800	$ 444	281,134	772,851	(21,571)	(72,058)
Balance (in shares) at Sep. 30, 2020		43,476
Balance at Jun. 30, 2020	894,212	$ 444	277,625	716,038	(27,837)	(72,058)
Balance (in shares) at Jun. 30, 2020		43,473
Increase (Decrease) in Stockholders' Equity
Net income	67,057			67,057
Translation adjustment, net of tax	6,238				6,238
Pension adjustment, net of tax	28				28
Stock-based compensation	3,651		3,651
Shares issued from release of Restricted Stock Units	(162)		(162)
Shares issued from release of Restricted Stock Units (in shares)		3
Cash dividends declared on common stock	(10,244)			(10,244)
Common stock issued	20		20
Balance at Sep. 30, 2020	$ 960,800	$ 444	$ 281,134	$ 772,851	$ (21,571)	$ (72,058)
Balance (in shares) at Sep. 30, 2020		43,476