Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 256,216	$ 226,665	$ 438,917	$ 381,566
Regulatory balancing account revenue	8,738	17,634	30,010	133,482
Total operating revenue	264,954	244,299	468,927	515,048
Total non-regulated revenue	4,911	5,513	9,992	10,611
Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	141,929	122,251	247,362	214,744
Business
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	48,094	41,906	88,642	76,455
Multiple residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	20,723	18,043	39,926	34,912
Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,529	7,119	12,934	13,759
Public authorities
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	13,011	10,918	22,256	17,880
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	25,930	26,428	27,797	23,816
Contract operating and maintenance revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,239	3,188	6,506	6,436
Other non-regulated revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,091	1,720	2,339	2,949
Non-regulated revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,330	4,908	8,845	9,385
Lease revenue	581	605	1,147	1,226
Total non-regulated revenue	$ 4,911	$ 5,513	$ 9,992	$ 10,611