Income Taxes (Tables)

9 Months Ended

Sep. 30, 2022

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

The following table summarizes the differences between our effective tax rate and the federal statutory rate (in thousands):

	Three Months Ended September 30,
	2022				2021
Income before income taxes	$	27,119			$	37,707
Income tax calculated at federal statutory rate	5,697		21.0	%	7,918		21.0	%
Permanent or flow-through adjustments:
State income tax, net of federal provisions	145		0.5		397		1.1
Flow-through repairs deductions	(3,374)		(12.4)		(3,473)		(9.2)
Production tax credits	(1,668)		(6.2)		(1,877)		(5.0)
Income tax return to accrual adjustment	(926)		(3.4)		389		1.0
Amortization of excess deferred income tax	(246)		(0.9)		(126)		(0.3)
Share-based compensation	—		—		(62)		(0.2)
Plant and depreciation of flow-through items	266		1.0		(288)		(0.8)
Other, net	(143)		(0.5)		(367)		(1.0)
	(5,946)		(21.9)		(5,407)		(14.4)
Income tax (benefit) expense	$	(249)	(0.9)	%	$	2,511	6.6	%

	Nine Months Ended September 30,
	2022				2021
Income before income taxes	$	118,561			$	139,358
Income tax calculated at federal statutory rate	24,897		21.0	%	29,265		21.0	%
Permanent or flow through adjustments:
State income, net of federal provisions	976		0.8		674		0.5
Flow-through repairs deductions	(13,488)		(11.4)		(15,553)		(11.2)
Production tax credits	(8,050)		(6.8)		(8,446)		(6.1)
Income tax return to accrual adjustment	(926)		(0.8)		389		0.3
Amortization of excess deferred income tax	(819)		(0.7)		(534)		(0.4)
Share-based compensation	(253)		(0.2)		(323)		(0.2)
Plant and depreciation of flow through items	409		0.3		(812)		(0.6)
Other, net	(449)		(0.3)		(806)		(0.5)
	(22,600)		(19.1)		(25,411)		(18.2)
Income tax expense	$	2,297	1.9	%	$	3,854	2.8	%