Discontinued Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018
Disposal Group, Including Discontinued Operation, Classified Balance Sheet Disclosures [Abstract]
Discontinued operations - current assets	$ 14,612	$ 12,644	$ 14,612	$ 12,644		$ 13,269
Discontinued operations - total assets		12,600		12,600
Discontinued operations current liabilities	13,399	13,003	13,399	13,003		12,959
Discontinued Operation, Income Statement Disclosures [Abstract]
Loss from discontinued operations, net of tax	$ (795)	$ (650)	$ (1,968)	$ (1,783)
Loss from discontinued operations per share of common stock
Basic (in dollars per share)	$ (0.02)	$ (0.02)	$ (0.07)	$ (0.06)
Diluted (in dollars per share)	$ (0.02)	$ (0.02)	$ (0.07)	$ (0.06)
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	$ 907	$ 395	$ 907	$ 395		390
Inventories	712	661	712	661		685
Other current assets	45	107	45	107		333
Property, plant, and equipment	12,589	11,241	12,589	11,241		11,621
Less: Accumulated depreciation	6	7	6	7		7
Operating lease right of use asset	118	0	118	0		0
Other non-current assets	247	247	247	247		247
Discontinued operations - total assets	14,612	12,644	14,612	12,644		13,269
Accounts payable	1,375	751	1,375	751		873
Other current liabilities	342	405	342	405		307
Operating lease liabilities	114	0	114	0		0
Other non-current liabilities	11,568	11,847	11,568	11,847		11,779
Total discontinued operations liabilities	13,399	13,003	13,399	13,003		$ 12,959
Gill Ranch [Member] | Discontinued Operations, Held-for-sale [Member]
Discontinued Operation, Income Statement Disclosures [Abstract]
Revenues	1,410	748	4,879	2,831
Operations and maintenance	2,113	1,549	6,377	4,139
General taxes, net		(261)
General taxes	40		159	419
Depreciation and amortization	105	106	317	324
Other expenses and interest	233	237	699	371
Total expenses	2,491	1,631	7,552	5,253
Loss from discontinued operations before income tax	(1,081)	(883)	(2,673)	(2,422)
Income tax benefit	(286)	(233)	(705)	(639)
Loss from discontinued operations, net of tax	$ (795)	$ (650)	$ (1,968)	$ (1,783)
Loss from discontinued operations per share of common stock
Basic (in dollars per share)	$ (0.02)	$ (0.02)	$ (0.07)	$ (0.06)
Diluted (in dollars per share)	$ (0.02)	$ (0.02)	$ (0.07)	$ (0.06)
Transferred Subsidiaries - NW Natural Discontinued Operations [Member] | Discontinued Operations, Disposed of by Means Other than Sale [Member]
Disposal Group, Including Discontinued Operation, Classified Balance Sheet Disclosures [Abstract]
Cash		$ 21,079		$ 21,079
Accounts receivable		517		517
Receivables from affiliates		3,791		3,791
Inventories		679		679
Other current assets		161		161
Property, plant, and equipment		14,732		14,732
Less: Accumulated depreciation		221		221
Other investments		13,654		13,654
Goodwill		6,563		6,563
Other non-current assets		351		351
Discontinued operations - current assets		26,227		26,227
Discontinued operations - non-current assets		35,079		35,079
Discontinued operations - total assets		61,306		61,306
Accounts payable		1,292		1,292
Taxes accrued		99		99
Payables to affiliates		939		939
Other current liabilities		1,439		1,439
Long-term debt		834		834
Deferred tax liabilities		(14,696)		(14,696)
Other non-current liabilities		11,932		11,932
Discontinued operations current liabilities		3,769		3,769
Discontinued operations non-current liabilities		(1,930)		(1,930)
Total discontinued operations liabilities		(1,839)		(1,839)
Discontinued Operation, Income Statement Disclosures [Abstract]
Revenues		818		3,016
Operations and maintenance		1,408		4,151
General taxes, net		(255)
General taxes				448
Depreciation and amortization		138		420
Other expenses and interest		232		342
Total expenses		1,523		5,361
Loss from discontinued operations before income tax		(705)		(2,345)
Income tax benefit		(186)		(622)
Loss from discontinued operations, net of tax		$ (519)		$ (1,723)
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%
Scenario, 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
Scenario, 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