Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Restricted Stock Units and Awards	Performance share units	Common Stock	Common Stock Restricted Stock Units and Awards	Common Stock Performance share units	Treasury Shares	Additional Paid-In Capital	Additional Paid-In Capital Restricted Stock Units and Awards	Additional Paid-In Capital Performance share units	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Common stock, beginning balance (in shares) at Dec. 31, 2020				134,144
Treasury stock, beginning balance (in shares) at Dec. 31, 2020							80,045
Beginning balance at Dec. 31, 2020	$ 702,620			$ 1,341			$ (595,297)	$ 740,970			$ 557,875	$ (2,269)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	58,816										58,816
Other comprehensive income	912											912
Share repurchases (in shares)							2,036
Share repurchases	(63,438)						$ (63,438)
Indirect repurchase of shares for minimum tax withholding (in shares)							92
Indirect repurchase of shares for minimum tax withholding	(3,037)						$ (3,037)
Restricted stock units and awards and Performance share units (in shares)				80
Restricted stock units and awards and Performance share units	0			$ 1				(1)
Stock options exercised (in shares)				493
Stock options exercised	5,448			$ 5				5,443
Stock-based compensation	5,454							5,454
Business acquisitions (in shares)				175
Business acquisitions	5,557			$ 2				5,555
Common stock, ending balance (in shares) at Jun. 30, 2021				134,892
Treasury stock, ending balance (in shares) at Jun. 30, 2021							82,173
Ending balance at Jun. 30, 2021	712,332			$ 1,349			$ (661,772)	757,421			616,691	(1,357)
Common stock, beginning balance (in shares) at Mar. 31, 2021				134,625
Treasury stock, beginning balance (in shares) at Mar. 31, 2021							81,209
Beginning balance at Mar. 31, 2021	727,783			$ 1,346			$ (629,439)	749,207			608,084	(1,415)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	8,607										8,607
Other comprehensive income	58											58
Share repurchases (in shares)							919
Share repurchases	(30,759)						$ (30,759)
Indirect repurchase of shares for minimum tax withholding (in shares)							45
Indirect repurchase of shares for minimum tax withholding	(1,574)						$ (1,574)
Restricted stock units and awards and Performance share units (in shares)		34
Stock options exercised (in shares)				96
Stock options exercised	1,040			$ 1				1,039
Stock-based compensation	2,599							2,599
Business acquisitions (in shares)				137
Business acquisitions	4,578			$ 2				4,576
Common stock, ending balance (in shares) at Jun. 30, 2021				134,892
Treasury stock, ending balance (in shares) at Jun. 30, 2021							82,173
Ending balance at Jun. 30, 2021	712,332			$ 1,349			$ (661,772)	757,421			616,691	(1,357)
Common stock, beginning balance (in shares) at Dec. 31, 2021				135,187
Treasury stock, beginning balance (in shares) at Dec. 31, 2021							83,149
Beginning balance at Dec. 31, 2021	704,548			$ 1,352			$ (694,716)	770,117			628,762	(967)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	89,382										89,382
Other comprehensive income	2,405											2,405
Share repurchases (in shares)							884
Share repurchases	(35,554)						$ (35,554)
Indirect repurchase of shares for minimum tax withholding (in shares)							188
Indirect repurchase of shares for minimum tax withholding	$ (7,289)						$ (7,289)
Restricted stock units and awards and Performance share units (in shares)					119	211
Restricted stock units and awards and Performance share units		$ 0	$ 0		$ 1	$ 2			$ (1)	$ (2)
Stock options exercised (in shares)	287			287
Stock options exercised	$ 3,896			$ 3				3,893
Stock-based compensation	6,428							6,428
Business acquisitions (in shares)				19
Business acquisitions	707							707
Common stock, ending balance (in shares) at Jun. 30, 2022				135,823
Treasury stock, ending balance (in shares) at Jun. 30, 2022							84,221
Ending balance at Jun. 30, 2022	764,523			$ 1,358			$ (737,559)	781,142			718,144	1,438
Common stock, beginning balance (in shares) at Mar. 31, 2022				135,756
Treasury stock, beginning balance (in shares) at Mar. 31, 2022							83,462
Beginning balance at Mar. 31, 2022	759,848			$ 1,358			$ (707,088)	777,731			686,889	958
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	31,255										31,255
Other comprehensive income	480											480
Share repurchases (in shares)							736
Share repurchases	(29,555)						$ (29,555)
Indirect repurchase of shares for minimum tax withholding (in shares)							23
Indirect repurchase of shares for minimum tax withholding	(916)						$ (916)
Restricted stock units and awards and Performance share units (in shares)		27
Stock options exercised (in shares)				40
Stock options exercised	672							672
Stock-based compensation	2,739							2,739
Common stock, ending balance (in shares) at Jun. 30, 2022				135,823
Treasury stock, ending balance (in shares) at Jun. 30, 2022							84,221
Ending balance at Jun. 30, 2022	$ 764,523			$ 1,358			$ (737,559)	$ 781,142			$ 718,144	$ 1,438