Income Taxes - Summary of Significant Factors Impact on Difference Between Effective Tax Rate and Federal Statutory Rate (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Federal income taxes at statutory rates	$ 2,294	$ (1,185)	$ 14,872	$ 13,764
Flow through related to deduction of meters and mixed service costs	(3,744)	1,192	(22,956)	(18,643)
Tax effect of regulatory treatment of utility plant differences	(828)	420	(6,040)	(6,878)
State income tax expense	151	(45)	949	856
Tax credits	(862)		(1,997)
Settlement of prior year tax returns	(867)	(318)	(867)	(318)
Uncertain tax positions	184		184
Other	(114)	93	(369)	(459)
Total income tax benefit	$ (3,786)	$ 157	$ (16,224)	$ (11,678)
Federal income taxes at statutory rates	21.00%	21.00%	21.00%	21.00%
Flow through related to deduction of meters and mixed service costs	(34.30%)	(21.10%)	(32.40%)	(28.40%)
Tax effect of regulatory treatment of utility plant differences	(7.60%)	(7.50%)	(8.50%)	(10.50%)
State income tax expense	1.40%	0.80%	1.30%	1.30%
Tax credits	(7.90%)		(2.80%)
Settlement of prior year tax returns	(7.90%)	5.60%	(1.20%)	(0.50%)
Uncertain tax positions	1.70%		0.20%
Other	(1.00%)	(1.60%)	(0.50%)	(0.70%)
Total income tax benefit	(34.60%)	(2.80%)	(22.90%)	(17.80%)