Jointly-Owned Facilities and Projects (Tables)

12 Months Ended

Dec. 31, 2018

Jointly-Owned Facilities and Projects [Abstract]

Jointly-Owned Facilities and Projects [Table Text Block]

Minnesota Power’s investments in jointly-owned facilities and projects and the related ownership percentages are as follows:

Regulated Utility Plant	Plant in Service		Accumulated Depreciation		Construction Work in Progress		% Ownership
Millions
As of December 31, 2018
Boswell Unit 4		$650.1		$229.9		$6.4	80
CapX2020	101.0		11.0		—		9.3 - 14.7
Total		$751.1		$240.9		$6.4
As of December 31, 2017
Boswell Unit 4		$668.2		$222.8		$8.2	80
CapX2020	101.0		8.4		—		9.3 - 14.7
Total		$769.2		$231.2		$8.2