Leases - Net Investment in Sales-Type Leases (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Mar. 31, 2019
Sales Type Leases Net Investment In Leases [Abstract]
Current minimum lease payments receivable			$ 1,201	$ 1,049
Non-current minimum lease payments receivable			889	715
Total minimum lease payments receivable			2,090	1,764
Less: Current unearned revenue			365	298
Less: Non-current unearned revenue			163	124
Net investment in sales-type leases	$ 1,342	$ 1,600	$ 1,562	$ 1,342

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 lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=119202524&loc=SL77919379-209981

Name:	us-gaap_SalesTypeLeaseLeaseReceivable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant