Allowance for Credit Losses (Financing Receivables by Credit Quality Indicator and by Class) (Details) - Notes Receivable [Member] $ in Thousands	Dec. 31, 2018 USD ($)
Financing Receivable, Recorded Investment [Line Items]
Notes Receivable	$ 70
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Notes Receivable	$ 70

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration