OPUC (Details 4) - Tax Cuts and Jobs Act [Member] - Natural gas rate proceeding [Member] - OPUC - USD ($)	Mar. 14, 2019	May 31, 2018
Public Utilities, General Disclosures [Line Items]
Public utilities, requested rate increase (decrease), amount		$ 2,300,000
Public utilities, requested rate increase (decrease), percentage		3.50%
Public Utilities, Approved Rate Increase (Decrease) in Revenues Only, Amount	$ 1,700,000
Public Utilities, Approved Rate Increase (Decrease) in Taxes Only, Amount	(500,000)
Public Utilities, Approved Rate Increase (Decrease), Amount	$ 1,200,000