Balance Sheet (Parentheticals) - Limited Partner [Member] - shares	Dec. 31, 2017	Dec. 31, 2016
Limited Partners, units authorized	24,000	24,000
Limited Partners, units issued	20,015	20,163
Limited Partners, units outstanding	20,015	20,163

The number of limited partner units authorized to be issued.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 4.F)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

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

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