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Regulatory Matters - Conservation Improvement Program (Details) (USD $) In Millions, unless otherwise specified | 3 Months Ended
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Sep. 30, 2014 | Dec. 31, 2013
Conservation Improvement Program [Abstract] |  |
CIP Energy-Savings Goal | 1.50% |
Conservation Improvement Program Financial Incentive | $ 8.7 | $ 7.1

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- Definition Minnesota's Next Generation Act of 2007 introduced an energy-savings goal of 1.5 percent of net gross annual retail electric energy sales beginning with the 2010 program year. + References No definition available. + Details
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- Details
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- Definition Conservation Improvement Program Financial Incentive + References No definition available. + Details
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