Lessor Leases - Sale-Type Lease Receivable Components (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2019	Dec. 31, 2018
Capital Leased Assets [Line Items]
Total future minimum sales-type lease payments	$ 34,057	$ 28,295
Present value adjustment	(3,116)	(2,477)
Net investment in sales-type leases	30,941	25,818
Less: Current portion	(9,447)	(8,736)
Long-term net investment in sales-type leases	$ 21,494	17,082
Minimum
Capital Leased Assets [Line Items]
Terms of sales-type leases (in years)	1 year
Maximum
Capital Leased Assets [Line Items]
Terms of sales-type leases (in years)	5 years
Allowance For Credit Losses
Capital Leased Assets [Line Items]
Sales-type Lease, Lease Receivable	$ 200	$ 200

Lessor Leasing Arrangements, Sales-Type Leases, Term of Contract

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Amount of net investment in sales-type and direct financing lease, classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=77888421&loc=SL77919306-209978

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=77888421&loc=SL77919308-209978

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Amount of net investment in sales-type and direct financing lease, classified as noncurrent.

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Present value of lease payments not yet received by lessor and amount expected to be derived from underlying asset, following end of lease term guaranteed by lessee or other third party unrelated to lessor, from sales-type and direct financing leases.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=119202524&loc=SL77919391-209981

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=119202524&loc=SL77919379-209981

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Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases.

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Amount of undiscounted lease receivable in excess of discounted receivable for sales-type and direct financing leases.

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-SubTopic 30
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=119202524&loc=SL77919379-209981

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