Allowance for Credit Losses (Net Investment in Financing Receivables by Age) (Details) - Notes Receivable [Member] $ in Thousands	Dec. 31, 2018 USD ($)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 70
Total financing receivables	$ 70

Financing receivables that are current.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953401-111524

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