Fair Value Measurements Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Business Acquisition, Contingent Consideration [Line Items]
Net gains associated with foreign currency derivatives	$ 600	$ 0
Business Combination, Contingent Consideration, Liability	10,600
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	(400)	$ 0
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High			$ 1,500
Fair Value, Measurements, Recurring [Member]
Business Acquisition, Contingent Consideration [Line Items]
Business Combination, Contingent Consideration, Liability	$ 12,052		$ 12,452