Reportable Segments - Schedule (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Revenue	$ 365,424	$ 345,558	$ 1,043,652	$ 1,011,157
Gross profit	103,878	102,811	295,763	297,013
Operating and other expenses	78,098	81,530	243,441	243,878
Income from continuing operations, before income taxes	25,780	21,281	52,322	53,135
Tech
Segment Reporting Information [Line Items]
Revenue	260,251	271,999	782,785	792,947
Gross profit	71,960	76,436	216,606	219,431
FA
Segment Reporting Information [Line Items]
Revenue	105,173	73,559	260,867	218,210
Gross profit	$ 31,918	$ 26,375	$ 79,157	$ 77,582