Pension and Other Postretirement Benefits (tables)

3 Months Ended

Mar. 31, 2013

General Discussion of Pension and Other Postretirement Benefits [Abstract]

Net Periodic Benefit Cost Components

	Three Months Ended Three Months Ended March 31,
							Other Postretirement
	Pension Benefits						Benefits
In thousands	2013			2012			2013			2012
Service cost	$	2,341		$	2,130		$	179		$	177
Interest cost	4,103			4,304			286			314
Expected return on plan assets	(4,678		)	(4,638		)	—			—
Amortization of net actuarial loss	4,421			3,843			169			103
Amortization of prior service costs	56			49			49			49
Amortization of transition obligations	—			—			—			103
Net periodic benefit cost	6,243			5,688			683			746
Amount allocated to construction	(1,855		)	(1,418		)	(219		)	(214		)
Amount deferred to regulatory balancing account(1)	(2,349		)	(2,068		)	—			—
Net amount charged to expense	$	2,039		$	2,202		$	464		$	532

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

In thousands
Beginning balance at December 31, 2012	$	(9,291	)
Amounts reclassified into AOCL	—
Amounts reclassified from AOCL:
Amortization of prior service costs	(2		)
Amortization of actuarial gains (losses)	386
Total reclassifications before tax	384
Tax expense	(151		)
Total reclassifications for the period	233
Ending balance at March 31, 2013	$	(9,058	)