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Commitments, Guarantees and Contingencies - Transmission (Details) (USD $) In Millions, unless otherwise specified | Dec. 31, 2012 | Dec. 31, 2011
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CapX2020 [Member] |  |
Transmission [Line Items] |  |
Number of Projects | 3 |
Minimum Amount Expected to be Invested in Transmission Projects | $ 100 |
Maximum Amount Expected to be Invested in Transmission Projects | 110 |
Capital Cost Spent to Date | 48.2 | 27.8
CapX2020 Fargo to Monticello Project [Member] |  |
Transmission [Line Items] |  |
Transmission Line Length (Miles) | 238 |
Transmission Line Capacity (kV) | 345 |
Capital Cost Spent to Date | 37.3 | 20.4
CapX2020 Monticello to St. Cloud Project [Member] |  |
Transmission [Line Items] |  |
Transmission Line Length (Miles) | 28 |
Transmission Line Capacity (kV) | 345 |
CapX2020 Bemidji to Grand Rapids Project [Member] |  |
Transmission [Line Items] |  |
Transmission Line Length (Miles) | 70 |
Transmission Line Capacity (kV) | 230 |
Capital Cost Spent to Date | $ 10.9 | $ 7.4

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- Definition Capital cost spent to date for project. + References No definition available. + Details
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- Definition The maximum amount expected to be invested in transmission line projects. + References No definition available. + Details
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- Definition The minimum amount expected to be invested in transmission line projects. + References No definition available. + Details
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- Definition Number of projects. + References No definition available. + Details
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- Definition Capacity of a transmission line in kilovolts. + References No definition available. + Details
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- Details
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- Definition Length of a transmission line in miles. + References No definition available. + Details
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