Supplemental Cash Flow - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 24,325	$ 18,559	$ 17,907
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	35,643	27,120	25,512	$ 35,454
Northwest Natural Gas Company [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	10,165	12,271	10,418
Restricted Cash	11,318	8,561	7,605
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	21,483	20,832	18,023	$ 15,739
Other Current Assets
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash	$ 11,318	$ 8,561	$ 7,605