Reporting Segments (Segment Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Segment operating revenues:
Gathering and transportation lease revenues	$ 59,090	$ 53,025
Total revenues	76,649	83,610
Segment operating costs:
Lease operating expenses	7,378	7,864
Transportation operating expenses	11,553	12,316
Production taxes	621	1,104
Gain on sale of assets		(3,186)
Depreciation, depletion and amortization	25,333	25,987
Asset impairments	32,119
Accretion expense	526	497
Total operating expenses	96,491	70,173
Segment other income (loss)
Earnings (loss) from equity investments	2,831	12,859
Segment operating income	1,950	51,887
Production
Segment operating revenues:
Total revenues	10,734	23,934
Segment operating costs:
Lease operating expenses	5,879	6,719
Production taxes	621	1,104
Gain on sale of assets		(3,186)
Depreciation, depletion and amortization	3,942	4,798
Accretion expense	200	198
Total operating expenses	10,642	9,633
Segment other income (loss)
Segment operating income	92	14,301
Midstream
Segment operating revenues:
Gathering and transportation lease revenues	59,090	53,025
Total revenues	65,915	59,676
Segment operating costs:
Lease operating expenses	1,499	1,145
Transportation operating expenses	11,553	12,316
Depreciation, depletion and amortization	21,391	21,189
Asset impairments	32,119
Accretion expense	326	299
Total operating expenses	66,888	34,949
Segment other income (loss)
Earnings (loss) from equity investments	2,831	12,859
Total segment other income (loss)	2,831	12,859
Segment operating income	1,858	37,586
Natural gas sales
Segment operating revenues:
Revenues	683	953
Natural gas sales | Production
Segment operating revenues:
Revenues	683	953
Oil sales
Segment operating revenues:
Revenues	9,512	21,272
Oil sales | Production
Segment operating revenues:
Revenues	9,512	21,272
Natural gas liquid sales
Segment operating revenues:
Revenues	539	1,709
Natural gas liquid sales | Production
Segment operating revenues:
Revenues	539	1,709
Gathering and transportation sales
Segment operating revenues:
Revenues	6,825	6,651
Gathering and transportation sales | Midstream
Segment operating revenues:
Revenues	$ 6,825	$ 6,651