Asset Retirement Obligation (Asset Retirement Obligation Transactions) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Asset Retirement Obligation [Abstract]
Balance	$ 2,270	$ 2,046
Accretion expense	141	141
Liabilities incurred	7	1
Liabilities settled	(41)	(45)
Liabilities sold properties		(11)
Revisions in estimated liabilities	(198)	138
Balance	$ 2,179	$ 2,270

Asset Retirement Obligation, Liabilities On Properties Sold

No definition available.

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- Definition

Asset Retirement Obligation Liabilities Settled, Net Of Properties Sold

+ References

No definition available.

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- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

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- Definition

Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848

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- References

No definition available.

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- Definition

Amount of asset retirement obligations incurred during the period.

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+ Details

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- Definition

Amount of increase (decrease) in the asset retirement obligation from changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)(4)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 35
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6392603&loc=d3e7123-110846

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