Assets for Lease, net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Assets for Lease, net
Lease revenue	$ 6,307	$ 5,951	$ 18,718	$ 16,608
Depreciation expense	146	124	318	361
Reduction to accumulated depreciation for returned items	56	38	143	115
Loss on disposal of assets for lease	$ (54)	$ (62)	$ (178)	$ (159)