Pension and Other Postretirement Benefits (tables)

9 Months Ended

Sep. 30, 2013

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	2013			2012			2013			2012
Service cost	$	2,341		$	2,130		$	178		$	177
Interest cost	4,103			4,303			286			314
Expected return on plan assets	(4,678		)	(4,637		)	—			—
Amortization of net actuarial loss	4,421			3,844			169			103
Amortization of prior service costs	56			48			50			50
Amortization of transition obligations	—			—			—			103
Net periodic benefit cost	6,243			5,688			683			747
Amount allocated to construction	(1,910		)	(1,676		)	(226		)	(252		)
Amount deferred to regulatory balancing account(1)	(2,230		)	(2,111		)	—			—
Net amount charged to expense	$	2,103		$	1,901		$	457		$	495

	Nine Months Ended September 30,
							Other Postretirement
	Pension Benefits						Benefits
In thousands	2013			2012			2013			2012
Service cost	$	7,023		$	6,390		$	536		$	531
Interest cost	12,310			12,911			858			943
Expected return on plan assets	(14,034		)	(13,914		)	—			—
Amortization of net actuarial loss	13,263			11,531			507			309
Amortization of prior service costs	167			146			148			148
Amortization of transition obligations	—			—			—			309
Net periodic benefit cost	18,729			17,064			2,049			2,240
Amount allocated to construction	(5,566		)	(4,522		)	(656		)	(681		)
Amount deferred to regulatory balancing account(1)	(6,850		)	(6,273		)	—			—
Net amount charged to expense	$	6,313		$	6,269		$	1,393		$	1,559

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

	Three Months Ended			Nine Months Ended
In thousands	September 30, 2013			September 30, 2013
Beginning balance	$	(8,826	)	$	(9,291	)
Amounts reclassified into AOCL	—			—
Amounts reclassified from AOCL:
Amortization of prior service costs	(1		)	(5		)
Amortization of actuarial losses	385			1,156
Total reclassifications before tax	384			1,151
Tax expense	(152		)	(454		)
Total reclassifications for the period	232			697
Ending balance	$	(8,594	)	$	(8,594	)