Condensed Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Revenue	$ 551,631	$ 567,597	$ 1,762,443	$ 1,635,215
Cost of revenue	366,998	377,566	1,178,204	1,088,883
Gross profit	184,633	190,031	584,239	546,332
Operating expenses:
Selling, general and administrative	111,235	133,207	394,537	374,872
Depreciation and amortization	26,936	17,085	69,096	41,513
Total operating expenses	138,171	150,292	463,633	416,385
Income from operations	46,462	39,739	120,606	129,947
Interest expense, net, and other	12,564	7,830	35,061	19,568
Income before income taxes	33,898	31,909	85,545	110,379
Income tax expense	7,831	8,394	24,188	23,873
Net income	26,067	23,515	61,357	86,506
Other comprehensive income (loss):
Foreign currency translation and other	(14)	132	(119)	(58)
Other comprehensive income (loss)	(14)	132	(119)	(58)
Comprehensive income	$ 26,053	$ 23,647	$ 61,238	$ 86,448
Net income per common share:
Basic (in dollars per share)	$ 0.55	$ 0.50	$ 1.29	$ 1.85
Diluted (in dollars per share)	$ 0.55	$ 0.49	$ 1.29	$ 1.82
Weighted average common shares outstanding:
Basic (shares)	47,476	46,677	47,406	46,701
Diluted (shares)	47,676	47,607	47,647	47,600