Reportable Segments - Operations of Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Revenue	$ 1,579,922	$ 1,397,700	$ 1,347,387
Gross profit	456,864	396,224	395,038
Operating and other expenses	357,597	321,012	323,642
Income from continuing operations, before income taxes	99,267	75,212	71,396
Technology
Segment Reporting Information [Line Items]
Revenue	1,273,941	1,049,628	1,057,859
Gross profit	355,971	289,720	292,980
FA
Segment Reporting Information [Line Items]
Revenue	305,981	348,072	289,528
Gross profit	$ 100,893	$ 106,504	$ 102,058