Financial Instruments - Investment In Financing Receivables On Nonaccrual Status (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Investment In Financing Receivables On Nonaccrual Status
Net investment in leases recorded investment	$ 0	$ 0
Net financed sales receivables recorded investment	1,149	967
Total recorded investment	1,149	967
Net investment in leases related allowance	0	0
Net financed sales receivables related allowance	(805)	(739)
Total related allowance	$ (805)	$ (739)