XML 43 R30.htm IDEA: XBRL DOCUMENT v3.5.0.2
Investment in ATC (Tables)
9 Months Ended
Sep. 30, 2016
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, 2015

$124.5

Cash Investments
3.5

Equity in ATC Earnings
15.0

Distributed ATC Earnings
(9.2
)
Equity Investment Balance as of September 30, 2016

$133.8