Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2017

Public Utilities, Property, Plant and Equipment [Abstract]

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

In thousands	2017		2016
Utility plant in service	$	2,975,217	$	2,843,243
Utility construction work in progress	159,924		62,264
Less: Accumulated depreciation	942,879		903,096
Utility plant, net	2,192,262		2,002,411
Non-utility plant in service	75,639		299,378
Non-utility construction work in progress	4,671		3,931
Less: Accumulated depreciation	17,598		44,820
Non-utility plant, net	62,712		258,489
Total property, plant, and equipment	$	2,254,974	$	2,260,900
Capital expenditures in accrued liabilities	$	34,976	$	9,547