Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of year	$ 7,272	$ 9,975	$ 12,255
Bad debt expense	573	(583)	337
Amount of receivables written off	(2,706)	(1,873)	(3,300)
Foreign currency translation and other	199	(247)	683
Balance at end of year	$ 5,338	$ 7,272	$ 9,975