Pension and Other Postretirement Benefits (tables)

3 Months Ended

Mar. 31, 2014

General Discussion of Pension and Other Postretirement Benefits [Abstract]

Net Periodic Benefit Cost Components

	Three Months Ended March 31,
							Other Postretirement
	Pension Benefits						Benefits
In thousands	2014			2013			2014			2013
Service cost	$	1,918		$	2,341		$	136		$	179
Interest cost	4,512			4,103			309			286
Expected return on plan assets	(4,886		)	(4,678		)	—			—
Amortization of net actuarial loss	2,580			4,421			46			169
Amortization of prior service costs	56			56			49			49
Net periodic benefit cost	4,180			6,243			540			683
Amount allocated to construction	(1,201		)	(1,855		)	(171		)	(219		)
Amount deferred to regulatory balancing account(1)	(1,101		)	(2,349		)	—			—
Net amount charged to expense	$	1,878		$	2,039		$	369		$	464

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

	Three Months Ended March 31,
In thousands	2014			2013
Beginning balance	$	(6,358	)	$	(9,291	)
Amounts reclassified from AOCL:
Amortization of prior service costs	(2		)	(2		)
Amortization of actuarial losses	276			386
Total reclassifications before tax	274			384
Tax expense	(109		)	(151		)
Total reclassifications for the period	165			233
Ending balance	$	(6,193	)	$	(9,058	)