Income Taxes (Tables)

9 Months Ended

Sep. 30, 2020

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,
	2020				2019
Income Before Income Taxes	$	26,763			$	22,225
Income tax calculated at federal statutory rate	5,621		21.0	%	4,667		21.0	%
Permanent or flow-through adjustments:
State income tax, net of federal provisions	46		0.2		65		0.3
Flow-through repairs deductions	(4,213)		(15.7)		(2,606)		(11.7)
Production tax credits	(2,205)		(8.2)		(1,414)		(6.3)
Amortization of excess deferred income tax	(222)		(0.8)		(374)		(1.7)
Plant and depreciation of flow-through items	103		0.4		(263)		(1.2)
Prior year permanent return to accrual adjustments	(1,728)		(6.5)		559		2.5
Other, net	(105)		(0.5)		(79)		(0.4)
	(8,324)		(31.1)		(4,112)		(18.5)
Income tax (benefit) expense	$	(2,703)	(10.1)	%	$	555	2.5	%

	Nine Months Ended September 30,
	2020				2019
Income Before Income Taxes	$	96,437			$	122,040
Income tax calculated at federal statutory rate	20,252		21.0	%	25,628		21.0	%
Permanent or flow through adjustments:
State income, net of federal provisions	73		0.1		1,230		1.0
Flow-through repairs deductions	(14,859)		(15.4)		(12,694)		(10.4)
Production tax credits	(7,553)		(7.8)		(7,252)		(5.9)
Share-based compensation	(609)		(0.6)		186		0.2
Amortization of excess deferred income tax	(731)		(0.8)		(1,939)		(1.6)
Prior year permanent return to accrual adjustments	(1,728)		(1.8)		559		0.4
Plant and depreciation of flow through items	299		0.3		(2,449)		(2.0)
Recognition of unrecognized tax benefit	—		—		(22,825)		(18.7)
Other, net	(371)		(0.4)		(542)		(0.5)
	(25,479)		(26.4)		(45,726)		(37.5)
Income tax benefit	$	(5,227)	(5.4)	%	$	(20,098)	(16.5)	%