Allowance for Credit Losses (Financing Receivables by Credit Quality Indicator and by Class) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Notes Receivable	$ 1,579	$ 3,623
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Notes Receivable	1,579	3,623
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Notes Receivable
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Notes Receivable
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Notes Receivable