Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Revenue	$ 1,591,194	$ 1,411,979	$ 1,104,925
Operating expenses	1,367,990	1,188,612	945,635
Gross margin	223,204	223,367	159,290
Corporate general and administrative expenses	57,965	55,023	56,150
Legal settlement, net	0	0	30,468
Operating income	165,239	168,344	72,672
Other income (expense):
Interest expense	(20,131)	(8,039)	(3,868)
Gain on sale of operations, net	176	413	5,995
Other income (expense), net	21,019	(19,243)	18,217
Total other income (expense), net	1,064	(26,869)	20,344
Income before income tax expense	166,303	141,475	93,016
Income tax expense	45,335	36,121	22,129
Net income	$ 120,968	$ 105,354	$ 70,887
Earnings per share:
Basic (in dollars per share)	$ 2.42	$ 2.05	$ 1.35
Diluted (in dollars per share)	$ 2.39	$ 2.01	$ 1.32
Basic weighted average common shares outstanding (in shares)	49,989	51,502	52,637
Diluted weighted average common shares outstanding (in shares)	50,557	52,388	53,723
Comprehensive income:
Net income	$ 120,968	$ 105,354	$ 70,887
Other comprehensive income (loss):
Net unrealized gain (loss) on available-for-sale securities, net of income tax expense (benefit) of $403, $(520) and $(179)	1,013	(1,391)	(478)
Net unrealized (loss) gain on interest rate swaps, net of income tax (benefit) expense of $(952), $1,965 and $577	(2,821)	5,986	1,799
Foreign currency translation	(18)	(24)	(19)
Total other comprehensive (loss) income	(1,826)	4,571	1,302
Total comprehensive income	$ 119,142	$ 109,925	$ 72,189