Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2018

Public Utilities, Property, Plant and Equipment [Abstract]

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

The following table sets forth the major classifications of property, plant, and equipment and accumulated depreciation at December 31:

In thousands	2018		2017
NW Natural:
NGD plant in service	$	3,134,122	$	2,975,217
NGD work in progress	204,978		159,924
Less: Accumulated depreciation	974,252		942,879
NGD plant, net	2,364,848		2,192,262
Other plant in service	66,009		64,997
Other construction work in progress	5,330		4,122
Less: Accumulated depreciation	18,603		17,406
Other plant, net(1)	52,736		51,713
Total property, plant, and equipment	$	2,417,584	$	2,243,975
Other (NW Holdings):
Other plant in service	$	4,051	$	375
Less: Accumulated depreciation	263		192
Other plant, net(1)	3,788		183
NW Holdings:
Total property, plant, and equipment	$	2,421,372	$	2,244,158
NW Natural and NW Holdings:
Capital expenditures in accrued liabilities	$	23,676	$	34,761

⁽¹⁾   NW Natural's previously reported other balances were restated due to certain assets and liabilities now being classified as discontinued operations assets and liabilities in its balance sheets. See Note 18 for further discussion.