Accounts Receivable - Allowance Activity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 11,074		$ 16,511
Write-offs	(2,675)	$ (2,321)	(18,614)	$ (2,321)
Additional provisions	1,043		1,830
Opening balance sheet adjustment related to ASU 2016 -13 adoption			10,097
Exchange differences	302		(80)
Ending balance	$ 9,744		$ 9,744