Income Tax (tables)

12 Months Ended

Dec. 31, 2014

Income Tax Disclosure [Abstract]

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

Dollars in thousands	2014			2013			2012
Income taxes at federal statutory rate	$	35,117		$	35,785		$	35,764
Increase (decrease):
Current state income tax, net of federal tax benefit	4,666			4,674			4,773
Amortization of investment tax credits	(201		)	(271		)	(350		)
Differences required to be flowed-through by regulatory commissions	2,357			2,357			1,718
Gains on company and trust-owned life insurance	(689		)	(864		)	(800		)
Regulatory asset impairment	—			—			2,700
Other, net	393			24			(402		)
Total provision for income taxes	$	41,643		$	41,705		$	43,403
Effective tax rate	41.5		%	40.8		%	42.5		%

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

In thousands	2014		2013			2012
Current
Federal	$	14,823	$	(62	)	$	1,693
State	24		(11		)	99
	14,847		(73		)	1,792
Deferred
Federal	18,635		35,109			31,187
State	8,161		6,669			10,424
	26,796		41,778			41,611
Total provision for income taxes	$	41,643	$	41,705		$	43,403
Total income taxes paid	$	19,445	$	870		$	2,979

Schedule Of Regulated Utility And Non Utility Business Segments [Table Text Block]

In thousands	2014			2013			2012
Utility:
Current	$	24,317		$	(73	)	$	1,909
Deferred	19,518			38,073			39,163
Deferred investment tax credits	(201		)	(271		)	(350		)
	43,634			37,729			40,722
Non-utility business segments:
Current	(9,470		)	—			(117		)
Deferred	7,479			3,976			2,798
	(1,991		)	3,976			2,681
Total provision for income taxes	$	41,643		$	41,705		$	43,403

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

In thousands	2014		2013
Deferred tax liabilities:
Plant and property	$	386,732	$	362,160
Regulatory income tax assets	51,805		56,183
Regulatory liabilities	55,776		71,971
Non-regulated deferred tax liabilities	48,683		47,516
Total	$	542,996	$	537,830
Deferred tax assets:
Pension and postretirement obligations	$	6,537	$	4,112
Alternative minimum tax credit carryforward	16,788		1,939
Loss and credit carryforwards	12,657		45,351
Total	35,982		51,402
Deferred income tax liabilities, net	507,014		486,428
Deferred investment tax credits	166		367
Deferred income taxes and investment tax credits	$	507,180	$	486,795