Property, Plant and Equipment (Tables)

3 Months Ended

Mar. 31, 2017

Public Utilities, Property, Plant and Equipment [Abstract]

Major Classifications Of Property, Plant And Equipment And Accumulated Depreciation [Text Block]

	March 31,				December 31,
In thousands	2017		2016		2016
Utility plant in service	$	2,867,271	$	2,760,188	$	2,843,243
Utility construction work in progress	76,631		51,014		62,264
Less: Accumulated depreciation	914,179		878,364		903,096
Utility plant, net	2,029,723		1,932,838		2,002,411
Non-utility plant in service	299,324		296,826		299,378
Non-utility construction work in progress	3,951		7,826		3,931
Less: Accumulated depreciation	46,157		40,823		44,820
Non-utility plant, net	257,118		263,829		258,489
Total property, plant, and equipment	$	2,286,841	$	2,196,667	$	2,260,900
Capital expenditures in accrued liabilities	$	11,564	$	8,424	$	9,547