Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Net service revenues	$ 1,319,238	$ 1,217,331	$ 1,073,728
Direct costs of services	905,124	842,750	729,352
Gross profit	414,114	374,581	344,376
Selling, general and administrative expenses	330,416	315,338	307,944
Goodwill impairment	0	0	14,510
Depreciation and amortization	9,831	9,894	9,846
Income from operations	73,867	49,349	12,076
Other expense (income):
Interest expense	1,982	1,411	1,225
Other expense (income)	213	(19)	(78)
Income from continuing operations, before income taxes	71,672	47,957	10,929
Income tax expense	28,848	18,559	5,635
Income from continuing operations	42,824	29,398	5,294
Income from discontinued operations, net of income taxes	0	61,517	5,493
Net income	42,824	90,915	10,787
Other comprehensive income (loss):
Defined benefit pension and post-retirement plans, net of tax	689	(688)	3,030
Comprehensive income	$ 43,513	$ 90,227	$ 13,817
Earnings per share – basic:
From continuing operations (in dollars per share)	$ 1.53	$ 0.94	$ 0.16
From discontinued operations (in dollars per share)	0.00	1.95	0.16
Earnings per share – basic (in dollars per share)	1.53	2.89	0.32
Earnings per share – diluted
From continuing operations (in dollars per share)	1.52	0.93	0.16
From discontinued operations (in dollars per share)	0.00	1.94	0.16
Earnings per share – diluted (in dollars per share)	$ 1.52	$ 2.87	$ 0.32
Weighted average shares outstanding - basic (in shares)	27,910	31,475	33,511
Weighted average shares outstanding – diluted (in shares)	28,190	31,691	33,643
Cash dividends declared per share (in dollars per share)	$ 0.45	$ 0.41	$ 0.10