Income Taxes (Tables)

9 Months Ended

Sep. 30, 2023

Income Tax Disclosure [Abstract]

Summary of Significant Factors Impact on Difference Between Effective Tax Rate and Federal Statutory Rate

The following table summarizes the significant factors impacting the difference between the Company's effective tax rate and the federal statutory rate for the three and nine months ended September 30 (dollars in thousands):

	Three months ended September 30,										Nine months ended September 30,
	2023					2022					2023					2022
Federal income taxes at statutory rates	$	2,294		21.0	%	$	(1,185	)	21.0	%	$	14,872		21.0	%	$	13,764		21.0	%
Increase (decrease) in tax resulting from:
Flow through related to deduction of meters      and mixed service costs (1)		(3,744	)	(34.3	)		1,192		(21.1	)		(22,956	)	(32.4	)		(18,643	)	(28.4	)
Tax effect of regulatory treatment of utility       plant differences		(828	)	(7.6	)		420		(7.5	)		(6,040	)	(8.5	)		(6,878	)	(10.5	)
State income tax expense		151		1.4			(45	)	0.8			949		1.3			856		1.3
Tax credits		(862	)	(7.9	)		—		—			(1,997	)	(2.8	)		—		—
Settlement of prior year tax returns		(867	)	(7.9	)		(318	)	5.6			(867	)	(1.2	)		(318	)	(0.5	)
Uncertain tax positions		184		1.7			—		—			184		0.2			—		—
Other		(114	)	(1.0	)		93		(1.6	)		(369	)	(0.5	)		(459	)	(0.7	)
Total income tax benefit	$	(3,786	)	(34.6	)%	$	157		(2.8	)%	$	(16,224	)	(22.9	)%	$	(11,678	)	(17.8	)%

(1)The Company's general rate cases included approval of base rate increases, offset by tax customer credits. As the tax customer credits are returned to customers, this results in a decrease to income tax expense as a result of flowing through the benefits related to meters and mixed service costs. The decrease in income tax expense offsets the increases in base rates granted to the Company in these general rate cases.