Investment in ATC (Tables)

9 Months Ended

Sep. 30, 2017

Equity Method Investments and Joint Ventures [Abstract]

ALLETE's Investment in ATC [Table Text Block]

ALLETE’s Investment in ATC
Millions
Equity Investment Balance as of December 31, 2016		$135.6
Cash Investments	6.6
Equity in ATC Earnings	17.3
Distributed ATC Earnings	(13.5		)
Equity Investment Balance as of September 30, 2017		$146.0