XML 46 R47.htm IDEA: XBRL DOCUMENT v2.4.1.9
ASSET RETIREMENT OBLIGATIONS (Tables)
 12 Months Ended
Dec. 31, 2014
Asset Retirement Obligation Disclosure [Abstract]  
Schedule of changes to asset retirement obligations
The following table shows changes to our asset retirement obligations through December 31, 2014:
(Millions)
 
 
 
Asset retirement obligations at December 31, 2011
 
$
18.6

 
Accretion
 
1.0

 
Revisions to estimated cash flows
 
(2.5
)
(1) 
Settlements
 
(0.4
)
 
Asset retirement obligations at December 31, 2012
 
16.7

 
Accretion
 
0.9

 
Revisions to estimated cash flows
 
0.5

 
Settlements
 
(0.1
)
 
Asset retirement obligations at December 31, 2013
 
18.0

 
Accretion
 
1.0

 
Revisions to estimated cash flows
 
1.5

(2) 
Settlements
 
(0.2
)
 
Asset retirement obligations at December 31, 2014
 
$
20.3

 

(1) 
Revisions were made to estimated cash flows related to asset retirement obligations for the PCB-contaminated transformers primarily due to changes in estimated removal costs, estimated settlement date, and transformer quantities.

(2) 
Revisions were made to estimated cash flows related to asset retirement obligations for the asbestos at electric generation facilities primarily due to changes in estimated settlement dates.