Acquisitions - Fair Value of Purchase Price (Details) - USD ($) $ in Thousands		12 Months Ended
	Jul. 01, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Cash consideration		$ 85,977	$ 1,900	$ 28,721
Advantage RN, LLC
Business Acquisition [Line Items]
Cash consideration	$ 86,562
Cash acquired	2,833
Total consideration	89,395
Purchase Price | Advantage RN, LLC
Business Acquisition [Line Items]
Purchase price	88,000
Net Working Capital Adjustments | Advantage RN, LLC
Business Acquisition [Line Items]
Purchase price	$ (1,438)