Accounts Receivable - Allowance Activity (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($)
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of year	$ 16,511
Additional provisions	0
Write-offs	(11,043)
Opening balance sheet adjustment related to ASU 2016 -13 adoption	10,097
Exchange differences	(493)
Balance at the end of year	$ 15,072