Discontinued Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2020	Dec. 31, 2019
Disposal Group, Including Discontinued Operation, Classified Balance Sheet Disclosures [Abstract]
Discontinued operations - total assets	$ 16,400	$ 14,000	$ 16,400	$ 14,000		$ 15,100
Discontinued Operation, Income Statement Disclosures [Abstract]
Loss from discontinued operations, net of tax	$ 280	$ (956)	$ (498)	$ (1,173)
Loss from discontinued operations per share of common stock
Basic (in dollars per share)	$ 0.01	$ (0.03)	$ (0.01)	$ (0.04)
Diluted (in dollars per share)	$ 0.01	$ (0.03)	$ (0.01)	$ (0.04)
Gill Ranch [Member] | Discontinued Operations, Held-for-sale or Disposed of by Sale [Member]
Disposal Group, Including Discontinued Operation, Classified Balance Sheet Disclosures [Abstract]
Accounts receivable	$ 1,621	$ 519	$ 1,621	$ 519		333
Inventories	821	756	821	756		695
Other current assets	250	183	250	183		457
Property, plant, and equipment	13,335	12,184	13,335	12,184		13,291
Less: Accumulated depreciation	7	6	7	6		7
Operating lease right of use asset	118	118	118	118		118
Other non-current assets	254	247	254	247		247
Discontinued operations - total assets	16,392	14,001	16,392	14,001		15,134
Accounts payable	999	1,230	999	1,230		1,250
Other current liabilities	1,119	296	1,119	296		848
Operating lease liabilities	112	113	112	113		116
Other non-current liabilities	11,344	11,640	11,344	11,640		11,495
Total discontinued operations liabilities	13,574	13,279	13,574	13,279		$ 13,709
Gill Ranch [Member] | Discontinued Operations, Held-for-sale [Member]
Discontinued Operation, Income Statement Disclosures [Abstract]
Revenues	3,374	1,748	4,282	3,469
Operations and maintenance	2,604	2,651	4,184	4,264
General taxes	53	60	100	119
Depreciation and amortization	106	106	212	212
Other expenses and interest	228	229	459	466
Total expenses	2,991	3,046	4,955	5,061
Loss from discontinued operations before income tax	383	(1,298)	(673)	(1,592)
Income tax benefit	103	(342)	(175)	(419)
Loss from discontinued operations, net of tax	$ 280	$ (956)	$ (498)	$ (1,173)
Loss from discontinued operations per share of common stock
Basic (in dollars per share)	$ 0.01	$ (0.03)	$ (0.01)	$ (0.04)
Diluted (in dollars per share)	$ 0.01	$ (0.03)	$ (0.01)	$ (0.04)
Gill Ranch [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percent ownership	75.00%		75.00%
Pacific Gas and Electric Company [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percent ownership	25.00%		25.00%
Forecast [Member] | Minimum [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestiture of businesses					$ 25,000
Forecast [Member] | Maximum [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestiture of businesses					$ 26,500