Reporting Segments Total depreciation and amortization by reporting segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total depreciation and amortization	$ 10,300	$ 11,679	$ 10,717
Enterprise Talent [Member]
Segment Reporting Information [Line Items]
Total depreciation and amortization	1,070	1,253	1,038
Specialty Talent and Technology [Member]
Segment Reporting Information [Line Items]
Total depreciation and amortization	2,632	2,483	368
Engineering Solutions [Member]
Segment Reporting Information [Line Items]
Total depreciation and amortization	4,630	5,724	6,231
MRI [Member]
Segment Reporting Information [Line Items]
Total depreciation and amortization	275	295	344
Corporate [Member]
Segment Reporting Information [Line Items]
Total depreciation and amortization	$ 1,693	$ 1,924	$ 2,736