Transactions with Major Customers and Affiliates (Tables)

12 Months Ended

Dec. 31, 2020

Transactions with Major Customers and Affiliates [Abstract]

Schedule of revenue by major customers

During the periods presented, more than 10 percent of our operating revenues were generated from each of the following customers:

	Years Ended December 31,
	2020		2019		2018
	(Thousands)
Puget Sound Energy, Inc.	$	132,747	$	121,792	$	115,238
Northwest Natural Gas Company	48,893		48,891		49,126
Cascade Natural Gas Corporation	47,493		46,969		46,164