Pension and Other Postretirement Benefits (tables)

9 Months Ended

Sep. 30, 2014

General Discussion of Pension and Other Postretirement Benefits [Abstract]

Net Periodic Benefit Cost Components

	Three Months Ended September 30,
							Other Postretirement
	Pension Benefits						Benefits
In thousands	2014			2013			2014			2013
Service cost	$	1,919		$	2,341		$	136		$	178
Interest cost	4,511			4,103			309			286
Expected return on plan assets	(4,887		)	(4,678		)	—			—
Amortization of net actuarial loss	2,579			4,421			46			169
Amortization of prior service costs	56			56			50			50
Net periodic benefit cost	4,178			6,243			541			683
Amount allocated to construction	(1,242		)	(1,910		)	(177		)	(226		)
Amount deferred to regulatory balancing account(1)	(1,107		)	(2,230		)	—			—
Net amount charged to expense	$	1,829		$	2,103		$	364		$	457

	Nine Months Ended September 30,
							Other Postretirement
	Pension Benefits						Benefits
In thousands	2014			2013			2014			2013
Service cost	$	5,755		$	7,023		$	407		$	536
Interest cost	13,535			12,310			928			858
Expected return on plan assets	(14,659		)	(14,034		)	—			—
Amortization of net actuarial loss	7,739			13,263			138			507
Amortization of prior service costs	168			167			148			148
Net periodic benefit cost	12,538			18,729			1,621			2,049
Amount allocated to construction	(3,644		)	(5,566		)	(518		)	(656		)
Amount deferred to regulatory balancing account(1)	(3,331		)	(6,850		)	—			—
Net amount charged to expense	$	5,563		$	6,313		$	1,103		$	1,393

Schedule Of Accumulated Other Comprehensive Income Loss Rollforward [Table Text Block]

	Three Months Ended September 30,						Nine Months Ended September 30,
In thousands	2014			2013			2014			2013
Beginning balance	$	(6,027	)	$	(8,826	)	$	(6,358	)	$	(9,291	)
Amounts reclassified from AOCL:
Amortization of prior service costs	(1		)	(1		)	(5		)	(5		)
Amortization of actuarial losses	275			385			826			1,156
Total reclassifications before tax	274			384			821			1,151
Tax expense	(108		)	(152		)	(324		)	(454		)
Total reclassifications for the period	166			232			497			697
Ending balance	$	(5,861	)	$	(8,594	)	$	(5,861	)	$	(8,594	)