Members' Capital (Narrative) (Details) - shares	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Other Members Capital Account [Line Items]
Members capital account, Units issued	13,560,188	13,560,188
Members capital account, Units outstanding	13,560,188	13,560,188	13,560,188
Other Members capital account, Units authorized	15,000,000	15,000,000
Managing Member [Member]
Other Members Capital Account [Line Items]
Members capital account, Units issued	50	50

Number of common units issued of limited liability company (LLC).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Name:	us-gaap_CommonUnitIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant