Net Investment in Sales-Type Leases - Long Term Net Investment in Sales Type Leases (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Capital Leased Assets [Line Items]
Net minimum lease payments to be received	$ 27,553	$ 33,591
Less: Unearned interest income portion	(2,206)	(2,763)
Net investment in sales-type leases	25,347	30,828
Less: Short-term portion	(7,923)	(10,243)
Long-term investment in sales-type leases, net	17,424	20,585
Collective allowance for credit losses	$ 200	$ 300
Minimum
Capital Leased Assets [Line Items]
Terms of sales-type leases (generally up to five years in length) (in years)	1 year
Maximum
Capital Leased Assets [Line Items]
Terms of sales-type leases (generally up to five years in length) (in years)	5 years