Acquisitions (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired	$ 0	$ 500	$ 5,500
Finite-lived Intangible Assets Acquired			$ 4,900
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life			10 years
Goodwill, Acquired During Period			$ 600
Payment for Contingent Consideration Liability, Financing Activities	10,000	$ 0
Biotix Acquisition [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired			$ 105,000
Payment for Contingent Consideration Liability, Financing Activities	$ 10,000