Derivatives - Notional Amounts (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 0	$ (100)	$ 0	$ (100)
Derivatives not designated as hedges
Notional Disclosures [Abstract]
Derivative notional amounts	2,603		2,603		$ 3,195
Foreign exchange contracts | Derivatives not designated as hedges
Notional Disclosures [Abstract]
Derivative notional amounts	$ 2,603		$ 2,603		$ 3,195