Oil And Gas Properties (Narrative) (Details) - USD ($)	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017
Oil And Gas Properties [Abstract]
Depletion expense	$ 348,000	$ 414,000
Gain on asset retirement obligations	$ 8,000	$ 2,000

The noncash expense charged against earnings to recognize the consumption of oil and gas reserves that are part of an entities' assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Name:	us-gaap_DepletionOfOilAndGasProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration