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Asset Sales, Discontinued Operations, and Impairment Charges (Impairment Charges) (Details) (USD $) In Millions, unless otherwise specified | 1 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2010 | May 31, 2010 | Dec. 31, 2010
Exeter [Member] |  |  |
Investment Carrying Value Prior To Asset Impairment | $ 11 |  | $ 11
Investment Fair Value | 5 |  | 5
Discontinued Operation, Provision for Loss (Gain) on Disposal, before Income Tax |  |  | 6
Deferred Coal-Fueled Power Plant [Member] | Consumers Energy Company [Member] |  |  |
Megawatt Capacity |  |  | 830
Public Utilities, Property, Plant and Equipment, Amount of Loss (Recovery) on Plant Abandonment | $ 19 | $ 3 | $ 22

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- Definition Megawatt capacity of a power plant. + References No definition available. + Details
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- Definition Pretax provision recognizing a loss for initial, or subsequent, write-down to fair value (less cost to sell) of a disposal group that is classified as a component of the entity, which remains unsold as of the reporting date. May include the recognition of a pretax (gain) for a subsequent increase in fair value (less cost to sell), but not in excess of the cumulative loss previously recognized through write-downs. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6892542&loc=d3e957-107759 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 144 -Paragraph 43 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 144 -Paragraph 47 -Subparagraph b -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1361-107760 + Details
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- Definition The amount of loss or recovery of loss related to a plant abandonment. If the carrying amount of the abandoned plant exceeds the present value of future cost recoveries through the rate making process, a loss is recognized. Such charges do not meet the requirements of an extraordinary item. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 360 -Section 35 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=6500292&loc=d3e45741-110387 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Technical Bulletin (FTB) -Number 87-2 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 90 -Paragraph 3, 4, 5, 6 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 10 -Section E + Details
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