Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 154,900	$ 145,225
Regulatory balancing account revenue	115,849	(14,125)
Operating revenue	270,749	131,100
Total non-regulated revenue	5,098	4,623
Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	92,492	84,035
Business
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	34,549	31,974
Multiple residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	16,869	14,997
Industrial
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,640	5,634
Public authorities
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,962	6,425
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	(2,612)	2,160
Operating and maintenance revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,248	3,235
Other non-regulated revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,229	782
Non-regulated revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,477	4,017
Lease revenue	621	606
Total non-regulated revenue	$ 5,098	$ 4,623