REVENUE, DIRECT COSTS AND GROSS MARGIN Revenue, Direct Costs and Gross Margin (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenue Direct Costs And Gross Margin Line Items [Line Items]
Revenue	$ 113,591	$ 113,067	$ 216,996	$ 214,294
Direct costs	65,265	66,228	126,238	126,193
Gross margin	48,326	46,839	90,758	88,101
Contracting
Revenue Direct Costs And Gross Margin Line Items [Line Items]
Revenue	70,264	72,035	136,716	137,890
Direct costs	62,093	62,956	120,518	120,178
Gross margin	8,171	9,079	16,198	17,712
Permanent Recruitment
Revenue Direct Costs And Gross Margin Line Items [Line Items]
Revenue	32,190	29,491	60,208	56,062
Direct costs	708	611	1,216	1,185
Gross margin	31,482	28,880	58,992	54,877
Talent Management
Revenue Direct Costs And Gross Margin Line Items [Line Items]
Revenue	10,559	11,013	18,976	19,449
Direct costs	1,910	2,116	3,415	3,799
Gross margin	8,649	8,897	15,561	15,650
Other Than Temporary Contracting Permanent Recruitment and Talent Management [Domain]
Revenue Direct Costs And Gross Margin Line Items [Line Items]
Revenue	578	528	1,096	893
Direct costs	554	545	1,089	1,031
Gross margin	$ 24	$ (17)	$ 7	$ (138)