Reportable Segments - Schedule (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Revenue	$ 403,614	$ 343,020	$ 766,839	$ 678,228
Gross profit	118,931	97,361	217,613	191,885
Operating and other expenses	88,920	83,353	169,436	165,343
Income from operations, before income taxes	30,011	14,008	48,177	26,542
Tech
Segment Reporting Information [Line Items]
Revenue	310,728	255,750	590,288	522,534
Gross profit	88,235	72,192	162,515	144,646
FA
Segment Reporting Information [Line Items]
Revenue	92,886	87,270	176,551	155,694
Gross profit	$ 30,696	$ 25,169	$ 55,098	$ 47,239