Supplemental Cash Flow - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 72,375	$ 32,920	$ 140,821
Restricted Cash	16,883	16,704	15,173
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	89,258	49,624	155,994	$ 40,964
Money Market Funds, at Carrying Value	48,800		112,600
Northwest Natural Gas Company [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	61,906	19,841	129,731
Restricted Cash	16,858	16,679	15,173
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	78,764	$ 36,520	144,904	$ 24,671
Money Market Funds, at Carrying Value	$ 48,800		$ 107,600