v2.4.0.6

Commitments and Contingencies (Schedules of Future Minimum Rental Payments) (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009
Land and Other Operating Leases [Member] |  |  |  |
Operating Leased Assets [Line Items] |  |  |  |
Operating Leases, Future Minimum Payments Due, Current | $ 12 |  |  |
Operating Leases, Future Minimum Payments, Due in Two Years | 11 |  |  |
Operating Leases, Future Minimum Payments, Due in Three Years | 11 |  |  |
Operating Leases, Future Minimum Payments, Due in Four Years | 14 |  |  |
Operating Leases, Future Minimum Payments, Due in Five Years | 14 |  |  |
Operating Leases, Future Minimum Payments, Due Thereafter | 431 |  |  |
Operating Leases, Future Minimum Payments Due | 493 |  |  |
Greenleaf [Member] |  |  |  |
Operating Leased Assets [Line Items] |  |  |  |
Operating Leases, Future Minimum Payments Due | 17 |  |  |
KIAC [Member] |  |  |  |
Operating Leased Assets [Line Items] |  |  |  |
Operating Leases, Future Minimum Payments Due, Current | 24 |  |  |
Operating Leases, Future Minimum Payments, Due in Two Years | 24 |  |  |
Operating Leases, Future Minimum Payments, Due in Three Years | 24 |  |  |
Operating Leases, Future Minimum Payments, Due in Four Years | 23 |  |  |
Operating Leases, Future Minimum Payments, Due in Five Years | 22 |  |  |
Operating Leases, Future Minimum Payments, Due Thereafter | 74 |  |  |
Operating Leases, Future Minimum Payments Due | 191 |  |  |
Total Power Plant Leases [Member] |  |  |  |
Operating Leased Assets [Line Items] |  |  |  |
Operating Leases, Future Minimum Payments Due, Current | 31 |  |  |
Operating Leases, Future Minimum Payments, Due in Two Years | 31 |  |  |
Operating Leases, Future Minimum Payments, Due in Three Years | 27 |  |  |
Operating Leases, Future Minimum Payments, Due in Four Years | 23 |  |  |
Operating Leases, Future Minimum Payments, Due in Five Years | 22 |  |  |
Operating Leases, Future Minimum Payments, Due Thereafter | 74 |  |  |
Operating Leases, Future Minimum Payments Due | 208 |  |  |
Operating Leases, Rent Expense, Net | 53 |  | 60 | 60
Operting Lease Assets Total [Member] |  |  |  |
Operating Leased Assets [Line Items] |  |  |  |
Operating Leases, Future Minimum Payments Due, Current | 43 |  |  |
Operating Leases, Future Minimum Payments, Due in Two Years | 42 |  |  |
Operating Leases, Future Minimum Payments, Due in Three Years | 38 |  |  |
Operating Leases, Future Minimum Payments, Due in Four Years | 37 |  |  |
Operating Leases, Future Minimum Payments, Due in Five Years | 36 |  |  |
Operating Leases, Future Minimum Payments, Due Thereafter | 505 |  |  |
Operating Leases, Future Minimum Payments Due | 701 |  |  |
Office Equipment [Member] |  |  |  |
Operating Leased Assets [Line Items] |  |  |  |
Operating Leases, Future Minimum Payments Due, Current | 13 |  |  |
Operating Leases, Future Minimum Payments, Due in Two Years | 12 |  |  |
Operating Leases, Future Minimum Payments, Due in Three Years | 10 |  |  |
Operating Leases, Future Minimum Payments, Due in Four Years | 10 |  |  |
Operating Leases, Future Minimum Payments, Due in Five Years | 9 |  |  |
Operating Leases, Future Minimum Payments, Due Thereafter | 32 |  |  |
Operating Leases, Future Minimum Payments Due | 86 |  |  |
Operating Leases, Rent Expense, Net | 13 |  | 12 | 12
Greenleaf [Member] |  |  |  |
Operating Leased Assets [Line Items] |  |  |  |
Guarantee Obligations Balance On First Anniversary | 7 | [1] |  |
Guarantee Obligations Balance On Second Anniversary | 7 | [1] |  |
Guarantee Obligations Balance On Third Anniversary | 3 | [1] |  |
Guarantee Obligations Balance On Fourth Anniversary | 0 | [1] |  |
Guarantee Obligations Balance On Fifth Anniversary | 0 | [1] |  |
Guarantee Obligations Due After Five Years | $ 0 | [1] |  |
[1] | These are contingent off balance sheet obligations.

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- Definition The total of future contractually required payments on leases defined as operating. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 122 -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 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 16 -Subparagraph b(i) -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 Accounting Standards Codification -Topic 840 -SubTopic 10 -Section 55 -Paragraph 40 -Subparagraph (Note 3) -URI http://asc.fasb.org/extlink&oid=6584154&loc=d3e38371-112697 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6453985&loc=d3e41502-112717 + Details
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