Fair Value Measurements and Derivative Instruments - Balance Sheet Hedging Instruments (Details) - Foreign currency debt - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Derivative Instruments
Carrying value of non-derivative instrument designated as hedging instrument	$ 333,061	$ 358,078
Current portion of debt
Derivative Instruments
Carrying value of non-derivative instrument designated as hedging instrument	40,153	73,572
Long-term debt
Derivative Instruments
Carrying value of non-derivative instrument designated as hedging instrument	$ 292,908	$ 284,506