Income Taxes - Summary of Significant Factors Impact on Difference Between Effective Tax Rate and Federal Statutory Rate (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Federal income taxes at statutory rates	$ 12,753	$ 16,838
Flow through related to deduction of meters and mixed service costs	(17,434)
Tax effect of regulatory treatment of utility plant differences	(6,322)	(5,966)
State income tax expense	823	478
Settlement of equity awards	(19)	930
Other	(637)	(116)
Total income tax expense (benefit)	$ (10,836)	$ 12,164
Federal income taxes at statutory rates	21.00%	21.00%
Flow through related to deduction of meters and mixed service costs	(28.70%)
Tax effect of regulatory treatment of utility plant differences	(10.40%)	(7.40%)
State income tax expense	1.40%	0.60%
Settlement of equity awards		1.20%
Other	(1.10%)	(0.20%)
Total income tax expense (benefit)	(17.80%)	15.20%