Members' Capital (Narrative) (Details) - shares	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Other Members [Member]
Members Capital Account [Line Items]
Members capital account, Units issued	2,565,749		2,565,749
Members capital account, Units outstanding	2,565,749	2,565,749	2,565,749	2,565,749	2,565,749	2,551,749
Managing Member [Member]
Members Capital Account [Line Items]
Members capital account, Units issued	50		50
Maximum [Member] | Other Members [Member]
Members Capital Account [Line Items]
Members capital account, units authorized	15,000,000		15,000,000