UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Net service revenues	$ 336,460	$ 341,575	$ 993,708	$ 991,539
Direct costs of services	231,080	231,754	684,857	680,940
Gross profit	105,380	109,821	308,851	310,599
Selling, general and administrative expenses	87,918	84,167	259,073	249,714
Depreciation and amortization	2,075	2,579	6,654	7,402
Income from operations	15,387	23,075	43,124	53,483
Other expense, net	663	463	1,936	1,907
Income before income taxes	14,724	22,612	41,188	51,576
Income tax expense	5,704	9,067	17,654	20,653
Net income	9,020	13,545	23,534	30,923
Other comprehensive (loss) income:
Defined benefit pension plans, net of tax	(2)	1	(7)	3
Comprehensive income	$ 9,018	$ 13,546	$ 23,527	$ 30,926
Earnings per share – basic (in dollars per share)	$ 0.35	$ 0.49	$ 0.90	$ 1.10
Earnings per share – diluted (in dollars per share)	$ 0.34	$ 0.48	$ 0.89	$ 1.09
Weighted average shares outstanding – basic (in shares)	25,996	27,811	26,287	28,072
Weighted average shares outstanding – diluted (in shares)	26,173	28,132	26,449	28,318
Dividends declared per share (in dollars per share)	$ 0.12	$ 0.11	$ 0.36	$ 0.33