Summary of Significant Accounting Policies - Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Revenue from contracts with customers	$ 678,168	$ 586,918	$ 559,568
Alternative revenue programs, net	3,634	(1,312)	5,304
Other balancing and memorandum accounts and regulatory mechanisms, net	(17,123)	29,487	3,435
Rental income	5,684	5,605	5,379
Operating revenue	670,363	620,698	573,686
Regulated operating revenue, water surcharge	$ 4,085	$ 6,121	$ 5,691