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Regulatory Matters (Tables) | 12 Months Ended
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Dec. 31, 2014
Regulatory Matters [Abstract] |
Regulatory Assets and Liabilities [Table Text Block] |
Regulatory Assets and Liabilities |  |
As of December 31 | 2014 |  | 2013 |
Millions |  |
Current Regulatory Assets (a) |  |
Deferred Fuel Adjustment Clause |  | $16.3 |  |  | $23.0 |
Total Current Regulatory Assets | 16.3 |  | 23.0 |
Non-Current Regulatory Assets |  |
Defined Benefit Pension and Other Postretirement Benefit Plans (b) | 223.9 |  | 164.1 |
Cost Recovery Riders (c) | 59.7 |  | 39.6 |
Income Taxes | 46.6 |  | 35.3 |
Asset Retirement Obligations | 17.8 |  | 16.0 |
PPACA Income Tax Deferral | 5.0 |  | 5.0 |
Other | 4.3 |  | 3.8 |
Total Non-Current Regulatory Assets | 357.3 |  | 263.8 |
Total Regulatory Assets |  | $373.6 |  |  | $286.8 |
Non-Current Regulatory Liabilities |  |
Wholesale and Retail Contra AFUDC |  | $42.9 |  |  | $19.7 |
Plant Removal Obligations | 22.8 |  | 19.7 |
Income Taxes | 13.4 |  | 17.0 |
Defined Benefit Pension and Other Postretirement Benefit Plans (b) | 3.5 |  | 16.3 |
Other | 11.6 |  | 8.3 |
Total Non-Current Regulatory Liabilities |  | $94.2 |  |  | $81.0 |
(a) | Current regulatory assets are included in Prepayments and Other on the Consolidated Balance Sheet.
(b) | Defined benefit pension and other postretirement items included in our Regulated Operations, which are otherwise required to be recognized in accumulated other comprehensive income, are recognized as regulatory assets or regulatory liabilities on the Consolidated Balance Sheet. (See Note 17. Pension and Other Postretirement Benefit Plans.)
(c) | The cost recovery rider regulatory assets are due to capital expenditures related to our Bison Wind Energy Center, investment in CapX2020 projects, and the Boswell Unit 4 environmental upgrade and are recognized in accordance with the accounting standards for alternative revenue programs.

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