Acquisitions (Details) $ in Thousands	Aug. 08, 2017 USD ($)
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Aug. 08, 2017
Business Acquisition, Name of Acquired Entity	StratAcuity Staffing Partners, Inc.
Business Acquisition, Description of Acquired Entity	headquartered in New Hampshire
Payments to Acquire Businesses, Gross	$ 25,900
Business Combination, Reason for Business Combination	was purchased to expand the Company's specialized clinical/scientific staffing solutions for biotechnology and pharmaceutical organizations
Business Acquisition, Goodwill, Expected Tax Deductible Amount	$ 17,500
Apex Segment [Member] | Stratacuity [Member]
Business Acquisition [Line Items]
Intangible Assets, Net (Excluding Goodwill)	$ 7,615