Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Revenue	$ 626,395	$ 598,290	$ 521,212
Cost of services:
Compensation	231,321	224,893	202,049
Direct project and other operating expenses	90,069	74,346	69,772
Information technology	53,950	53,428	45,723
Occupancy	16,375
Occupancy		15,968	17,190
Amortization of acquisition related software and intangible assets	16,999	32,975	30,393
Total cost of services	408,714	401,610	365,127
Selling, general and administrative expenses	114,665	113,442	105,654
Settlement expense	0	20,000	0
Total operating expenses	523,379	535,052	470,781
Operating income	103,016	63,238	50,431
Interest Expense	(11,013)	(11,310)	(10,871)
Interest income	4,148	1,089	295
Other income	8,211	0	0
Income before income taxes	104,362	53,017	39,855
Income taxes	17,138	(1,972)	(199)
Net income	$ 87,224	$ 54,989	$ 40,054
Basic income per common share:
Net income per common share - basic (in dollars per share)	$ 1.00	$ 0.66	$ 0.48
Diluted income per common share:
Net income per common share -- diluted (in dollars per share)	$ 0.98	$ 0.64	$ 0.47
Weighted average shares:
Basic (in shares)	87,222	83,625	83,821
Diluted (in shares)	89,317	86,144	85,088