Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 306,237	$ 253,337	$ 687,803	$ 592,768
Regulatory balancing account revenue	(6,674)	1,639	126,808	(12,648)
Total operating revenue	299,563	254,976	814,611	580,120
Total non-regulated revenue	4,133	4,535	14,744	13,643
Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	184,951	150,031	399,695	342,806
Business
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	56,225	47,707	132,680	117,527
Multiple residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	21,795	18,778	56,707	50,280
Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	9,645	8,165	23,404	19,672
Public authorities
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	18,140	14,522	36,020	29,938
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	15,481	14,134	39,297	32,545
Operating and maintenance revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,384	2,918	9,820	9,229
Other non-regulated revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	143	972	3,092	2,553
Non-regulated revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,527	3,890	12,912	11,782
Lease revenue	606	645	1,832	1,861
Total non-regulated revenue	$ 4,133	$ 4,535	$ 14,744	$ 13,643