Schedule II Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 2,796	$ 5,930	$ 5,050
Charged (Credited) to Cost and Expenses	2,499	(117)	946
Debited (Credited) to Other Accounts	0	24	3
Amount Written Off	(1,986)	(3,010)	(402)
Translation Adjustments	143	(31)	333
Balance at End of Period	3,452	2,796	5,930
Accounts Receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	2,582	5,738	4,796
Charged (Credited) to Cost and Expenses	2,488	(127)	1,008
Debited (Credited) to Other Accounts	0	12	3
Amount Written Off	(1,986)	(3,010)	(402)
Translation Adjustments	143	(31)	333
Balance at End of Period	3,227	2,582	5,738
Investment in sales-type leases
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	214	192	254
Charged (Credited) to Cost and Expenses	11	10	(62)
Debited (Credited) to Other Accounts	0	12	0
Amount Written Off	0	0	0
Translation Adjustments	0	0	0
Balance at End of Period	$ 225	$ 214	$ 192