XML 35 R44.htm IDEA: XBRL DOCUMENT v2.4.0.6
Regulatory Matters - Regulatory Assets and Liabilities (Details) (USD $)
In Millions, unless otherwise specified
Sep. 30, 2012
Dec. 31, 2011
Regulatory Assets and Liabilities [Line Items]    
Current Regulatory Assets $ 18.2 $ 17.5
Non-Current Regulatory Assets 334.6 345.9
Total Regulatory Assets 352.8 363.4
Non-Current Regulatory Liabilities 54.8 43.5
Income Taxes [Member]
    
Regulatory Assets and Liabilities [Line Items]    
Non-Current Regulatory Liabilities 19.8 21.9
Plant Removal Obligations [Member]
    
Regulatory Assets and Liabilities [Line Items]    
Non-Current Regulatory Liabilities 17.5 15.0
Wholesale and Retail Contra AFUDC [Member]
    
Regulatory Assets and Liabilities [Line Items]    
Non-Current Regulatory Liabilities 11.1 1.5
Other [Member]
    
Regulatory Assets and Liabilities [Line Items]    
Non-Current Regulatory Liabilities 6.4 5.1
Deferred Fuel [Member]
    
Regulatory Assets and Liabilities [Line Items]    
Current Regulatory Assets 18.2 [1] 17.5 [1]
Future Benefit Obligations Under Defined Benefit Pension and Other Postretirement Benefit Plans [Member]
    
Regulatory Assets and Liabilities [Line Items]    
Non-Current Regulatory Assets 276.6 292.8
Income Taxes [Member]
    
Regulatory Assets and Liabilities [Line Items]    
Non-Current Regulatory Assets 28.2 28.6
Asset Retirement Obligation [Member]
    
Regulatory Assets and Liabilities [Line Items]    
Non-Current Regulatory Assets 11.5 9.8
Cost Recovery Riders [Member]
    
Regulatory Assets and Liabilities [Line Items]    
Non-Current Regulatory Assets 11.4 [2] 0.7 [2]
PPACA Income Tax Deferral [Member]
    
Regulatory Assets and Liabilities [Line Items]    
Non-Current Regulatory Assets 5.0 5.0
Other [Member]
    
Regulatory Assets and Liabilities [Line Items]    
Non-Current Regulatory Assets $ 1.9 [3] $ 9.0
[1] Current regulatory assets are included in prepayments and other on the Consolidated Balance Sheet.
[2] The increase in cost recovery rider regulatory assets is primarily due to higher capital expenditures related to our Bison projects.
[3] The decrease in Other is primarily due to the Conservation Improvement Program incentive recorded in 2011 and collected in 2012.