Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Components of income before income taxes

The components of income before income taxes from continuing operations for each of the years ended December 31 were as follows:



	2019			2018			2017
	(In thousands)
United States	$	398,532		$	317,655		$	350,064
Foreign	(87		)	(784		)	(37		)
Income before income taxes from continuing operations	$	398,445		$	316,871		$	350,027

Income tax expense

Income tax expense (benefit) from continuing operations for the years ended December 31 was as follows:



	2019			2018			2017
	(In thousands)
Current:
Federal	$	(3,502	)	$	(15,901	)	$	74,272
State	3,366			3,651			16,192
	(136		)	(12,250		)	90,464
Deferred:
Income taxes:
Federal	50,218			50,755			(24,497		)
State	12,098			7,206			(864		)
Investment tax credit - net	1,099			1,774			(62		)
	63,415			59,735			(25,423		)
Total income tax expense	$	63,279		$	47,485		$	65,041

Deferred tax assets and deferred tax liabilities

Components of deferred tax assets and deferred tax liabilities at December 31 were as follows:



	2019		2018
	(In thousands)
Deferred tax assets:
Postretirement	$	51,075	$	51,930
Compensation-related	37,330		29,885
Operating lease liabilities	24,459		—
Asset retirement obligations	7,450		7,083
Customer advances	7,325		7,734
Legal and environmental contingencies	6,601		6,729
Federal renewable energy credit	5,343		8,015
Alternative minimum tax credit carryforward	—		13,404
Other	32,533		37,347
Total deferred tax assets	172,116		162,127
Deferred tax liabilities:
Depreciation and basis differences on property, plant and equipment	511,867		476,832
Postretirement	48,927		44,432
Operating lease right-of-use-assets	24,436		—
Intangible asset amortization	18,930		17,752
Other	61,385		39,712
Total deferred tax liabilities	665,545		578,728
Valuation allowance	13,154		13,484
Net deferred income tax liability	$	506,583	$	430,085

Schedule of change in net deferred income tax liability reconciliation

The following table reconciles the change in the net deferred income tax liability from December 31, 2018, to December 31, 2019, to deferred income tax expense:



	2019
(In thousands)
Change in net deferred income tax liability from the preceding table	$	76,498
Deferred taxes associated with other comprehensive loss	1,631
Deferred taxes associated with TCJA enactment for regulated activities	(11,904		)
Other	(2,810		)
Deferred income tax expense for the period	$	63,415

Reconciliation of income tax expense (benefit) at statutory federal rate versus actual rate

Total income tax expense differs from the amount computed by applying the statutory federal income tax rate to income before taxes. The reasons for this difference were as follows:



Years ended December 31,	2019					2018					2017
	Amount			%		Amount			%		Amount			%
	(Dollars in thousands)
Computed tax at federal statutory rate	$	83,674		21.0		$	66,543		21.0		$	122,509		35.0
Increases (reductions) resulting from:
State income taxes, net of federal income tax	14,029			3.5		12,190			3.8		10,724			3.1
Federal renewable energy credit	(15,843		)	(4.0	)	(11,759		)	(3.7	)	(13,958		)	(4.0	)
Tax compliance and uncertain tax positions	(2,739		)	(.7	)	(2,725		)	(.9	)	(643		)	(.2	)
Domestic production deduction	—			—		—			—		(6,849		)	(2.0	)
Excess deferred income tax amortization	(11,904		)	(3.0	)	(9,319		)	(2.9	)	(397		)	—
TCJA revaluation	—			—		(5,947		)	(1.9	)	(47,242		)	(13.5	)
TCJA revaluation related to accumulated other comprehensive loss balance	—			—		(42		)	—		7,735			2.2
Other	(3,938		)	(.9	)	(1,456		)	(.4	)	(6,838		)	(2.0	)
Total income tax expense	$	63,279		15.9		$	47,485		15.0		$	65,041		18.6