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Jointly-Owned Facilities (Details) (USD $) In Millions, unless otherwise specified | Dec. 31, 2012
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Jointly-Owned Facilities [Line Items] |
Plant in Service | $ 435.9
Accumulated Depreciation | 188.5
Construction Work in Progress | 50.4
Boswell Unit 4 [Member] |
Jointly-Owned Facilities [Line Items] |
Plant in Service | 413.1
Accumulated Depreciation | 188.1
Construction Work in Progress | 25.0
% Ownership | 80.00%
Generating Unit Capacity (MW) | 585
% Not Owned | 20.00%
CapX2020 [Member] |
Jointly-Owned Facilities [Line Items] |
Plant in Service | 22.8
Accumulated Depreciation | 0.4
Construction Work in Progress | $ 25.4
Number of Projects | 3
CapX2020 [Member] | Minimum [Member] |
Jointly-Owned Facilities [Line Items] |
% Ownership | 9.30%
CapX2020 [Member] | Maximum [Member] |
Jointly-Owned Facilities [Line Items] |
% Ownership | 14.70%

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- Definition Capacity of each generating unit/individual project in megawatts. + References No definition available. + Details
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- Definition Jointly-Owned Electric Facility Percentage Not Owned + References No definition available. + Details
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- Definition Number of projects. + References No definition available. + Details
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- Definition The period end amount owned by the reporting utility of a jointly owned utility plant in service. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 10.C) -URI http://asc.fasb.org/extlink&oid=6500719&loc=d3e659983-123033 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 10 -Section C + Details
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- Details
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- Definition The period end amount of construction work in progress at a jointly owned electricity generation plant. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 10.C) -URI http://asc.fasb.org/extlink&oid=6500719&loc=d3e659983-123033 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 10 -Section C + Details
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- Definition The period end amount of accumulated depreciation in a jointly owned electricity generation plant. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 10.C) -URI http://asc.fasb.org/extlink&oid=6500719&loc=d3e659983-123033 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 10 -Section C + Details
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- Definition The proportionate share of interest (percent) in a jointly owned utility plant. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 10.C) -URI http://asc.fasb.org/extlink&oid=6500719&loc=d3e659983-123033 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 10 -Section C + Details
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