Derivative Instruments (tables)

3 Months Ended

Mar. 31, 2015

Derivative Instruments, Gain (Loss) [Line Items]

Table Of Estimated Collateral Calls Table [Text Block]

			Credit Rating Downgrade Scenarios
In thousands	(Current Ratings)  A+/A3		BBB+/Baa1		BBB/Baa2		BBB-/Baa3		Speculative
With Adequate Assurance Calls	$	—	$	—	$	—	$	—	$	20,683
Without Adequate Assurance Calls	—		—		—		—		15,773

Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]

	March 31,				December 31,
In thousands	2015		2014		2014
Natural gas (in therms):
Financial	229,925		295,125		287,475
Physical	250,250		875,150		420,980
Foreign exchange	$	8,690	$	5,590	$	12,230

Income Statement Presentation of Derivative Instruments [Text Block]

	Three Months Ended March 31,
	2015						2014
In thousands	Natural gas commodity			Foreign currency			Natural gas commodity			Foreign currency
Benefit (expense) to cost of gas	$	(23,481	)	$	(741	)	$	15,912		$	275
Operating revenues	638			—			—			—
Less:
Amounts deferred to regulatory accounts on the balance sheet	23,065			741			(15,875		)	(275		)
Total gain in pre-tax earnings	$	222		$	—		$	37		$	—