Allowance for Credit Losses (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Allowance for Credit Losses [Abstract]
Allowance for credit losses	$ 190	$ 101
Credit loss netted against lease revenue	$ 89	$ 85

A valuation allowance for financing receivables that are expected to be uncollectible.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant