PROPERTY, PLANT, AND EQUIPMENT	3 Months Ended
Mar. 31, 2018
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT, AND EQUIPMENT	PROPERTY, PLANT, AND EQUIPMENT Wisconsin Segment Plant to be Retired We have evaluated future plans for our older and less efficient fossil fuel generating units and have announced the retirement of the plants identified below. The net book value of these plants was classified as plant to be retired within property, plant, and equipment on our balance sheet at March 31, 2018. In addition, severance expense in the amount of $29.4 million was recorded within the Wisconsin segment in 2017 related to these announced plant retirements. Pleasant Prairie Power Plant As a result of a MISO ruling in December 2017, the Pleasant Prairie power plant was retired effective April 10, 2018. Retirement of the Pleasant Prairie power plant was considered probable at March 31, 2018. The net book value of this generating unit was $674.1 million at March 31, 2018, and was classified as plant to be retired within property, plant, and equipment on our balance sheet. This unit is included in rate base, and WE continues to depreciate it on a straight-line basis using the composite depreciation rates approved by the PSCW. The physical dismantlement of the plant will not occur immediately. It may take several years to finalize long-term plans for the site. See Note 19, Commitments and Contingencies, for more information. Presque Isle Power Plant In October 2017, the MPSC approved UMERC’s application to construct and operate approximately 180 MW of natural gas-fired generation in the Upper Peninsula of Michigan. The new units are expected to begin commercial operation by mid-2019. Upon receiving the MPSC's approval, retirement of the PIPP generating units became probable. As a result of a MISO ruling received in April 2018, the PIPP units must be retired no later than May 31, 2019. The net book value of these units was $188.7 million at March 31, 2018, and was classified as plant to be retired within property, plant, and equipment on our balance sheet. These units are included in rate base, and WE continues to depreciate them on a straight-line basis using the composite depreciation rates approved by the PSCW. See Note 19, Commitments and Contingencies, and Note 21, Regulatory Environment, for more information. Pulliam Power Plant WPS anticipates retiring Pulliam generating units 7 and 8 near the end of 2018 when certain transmission lines are completed. Retirement of the Pulliam generating units was probable at March 31, 2018. The net book value of these generating units was $43.6 million at March 31, 2018, and was classified as plant to be retired within property, plant, and equipment on our balance sheet. These units are included in rate base, and WPS continues to depreciate them on a straight-line basis using the composite depreciation rates approved by the PSCW. See Note 19, Commitments and Contingencies, for more information. Edgewater Unit 4 As a result of the continued implementation of the Consent Decree related to the jointly owned Columbia and Edgewater plants, retirement of the Edgewater 4 generating unit was probable at March 31, 2018. The plant must be retired by September 30, 2018. The net book value of WPS's ownership share of this generating unit was $12.7 million at March 31, 2018, and was classified as plant to be retired within property, plant, and equipment on our balance sheet. This unit is included in rate base, and WPS continues to depreciate it on a straight-line basis using the composite depreciation rates approved by the PSCW. See Note 19, Commitments and Contingencies, for more information regarding the Consent Decree.

PROPERTY, PLANT, AND EQUIPMENT

Wisconsin Segment Plant to be Retired

We have evaluated future plans for our older and less efficient fossil fuel generating units and have announced the retirement of the plants identified below. The net book value of these plants was classified as plant to be retired within property, plant, and equipment on our balance sheet at March 31, 2018. In addition, severance expense in the amount of $29.4 million was recorded within the Wisconsin segment in 2017 related to these announced plant retirements.

Pleasant Prairie Power Plant

As a result of a MISO ruling in December 2017, the Pleasant Prairie power plant was retired effective April 10, 2018. Retirement of the Pleasant Prairie power plant was considered probable at March 31, 2018. The net book value of this generating unit was $674.1 million at March 31, 2018, and was classified as plant to be retired within property, plant, and equipment on our balance sheet. This unit is included in rate base, and WE continues to depreciate it on a straight-line basis using the composite depreciation rates approved by the PSCW. The physical dismantlement of the plant will not occur immediately. It may take several years to finalize long-term plans for the site. See Note 19, Commitments and Contingencies, for more information.

Presque Isle Power Plant

In October 2017, the MPSC approved UMERC’s application to construct and operate approximately 180 MW of natural gas-fired generation in the Upper Peninsula of Michigan. The new units are expected to begin commercial operation by mid-2019. Upon receiving the MPSC's approval, retirement of the PIPP generating units became probable. As a result of a MISO ruling received in April 2018, the PIPP units must be retired no later than May 31, 2019. The net book value of these units was $188.7 million at March 31, 2018, and was classified as plant to be retired within property, plant, and equipment on our balance sheet. These units are included in rate base, and WE continues to depreciate them on a straight-line basis using the composite depreciation rates approved by the PSCW. See Note 19, Commitments and Contingencies, and Note 21, Regulatory Environment, for more information.

Pulliam Power Plant

WPS anticipates retiring Pulliam generating units 7 and 8 near the end of 2018 when certain transmission lines are completed. Retirement of the Pulliam generating units was probable at March 31, 2018. The net book value of these generating units was $43.6 million at March 31, 2018, and was classified as plant to be retired within property, plant, and equipment on our balance sheet. These units are included in rate base, and WPS continues to depreciate them on a straight-line basis using the composite depreciation rates approved by the PSCW. See Note 19, Commitments and Contingencies, for more information.

Edgewater Unit 4

As a result of the continued implementation of the Consent Decree related to the jointly owned Columbia and Edgewater plants, retirement of the Edgewater 4 generating unit was probable at March 31, 2018. The plant must be retired by September 30, 2018. The net book value of WPS's ownership share of this generating unit was $12.7 million at March 31, 2018, and was classified as plant to be retired within property, plant, and equipment on our balance sheet. This unit is included in rate base, and WPS continues to depreciate it on a straight-line basis using the composite depreciation rates approved by the PSCW. See Note 19, Commitments and Contingencies, for more information regarding the Consent Decree.