v2.4.0.8

Risk Management Activities (Narrative) (Details) (USD $) | 0 Months Ended | 6 Months Ended |  | 6 Months Ended | 12 Months Ended | 6 Months Ended | 12 Months Ended |  | 6 Months Ended
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Sep. 16, 2005 | Jul. 22, 2003 | Jun. 30, 2013 | Jun. 30, 2012 | Dec. 31, 2012 | Jun. 30, 2013 Physical Sales Contracts Marked-To-Market [Member] | Dec. 31, 2012 Physical Sales Contracts Marked-To-Market [Member] | Jun. 30, 2013 Financial Derivative Contracts Marked To Market [Member] | Dec. 31, 2012 Financial Derivative Contracts Marked To Market [Member] | Sep. 16, 2005 5.25% - Due September 15, 2017 [Member] | Sep. 16, 2005 5.45% - Due September 15, 2020 [Member] | Jun. 30, 2013 Millennium Pipeline Company, L.L.C [Member] | Jun. 30, 2012 Millennium Pipeline Company, L.L.C [Member]
Derivative Instruments Gain Loss [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net |  |  | $ 0 | $ 0 |  |  |  |  |  |  |  |  |
Additional Collateral, Aggregate Fair Value |  |  | 800,000 |  |  |  |  |  |  |  |  |  |
Face amount of notes |  |  |  |  |  |  |  |  |  | 1,000,000,000 | 1,000,000,000 |  |
Reserves against physical sale contract derivatives |  |  | 300,000 |  | 700,000 |  |  |  |  |  |  |  |
Fair value of physical sales contracts and derivative contracts |  |  |  |  |  | 14,700,000 | 35,400,000 | (15,000,000) | (33,200,000) |  |  |  |
Outstanding debt |  |  | 7,400,000,000 |  |  |  |  |  |  |  |  |  |
Outstanding debt subject to interest rate fluctuations |  |  | 500,000,000 |  |  |  |  |  |  |  |  |  |
Derivative, Notional Amount | 900,000,000 | 500,000,000 |  |  |  |  |  |  |  |  |  |  |
Number of counterparties in swap agreement |  | 4 |  |  |  |  |  |  |  |  |  |  |
Fixed interest rate under swap agreement |  | 5.40% |  |  |  |  |  |  |  |  |  |  |
Floating interest amount, average interest addition |  | 0.78% |  |  |  |  |  |  |  |  |  |  |
Number of counterparties in swap agreement settled | 6 |  |  |  |  |  |  |  |  |  |  |  |
Payment for settlement of interest rate swap | 35,500,000 |  |  |  |  |  |  |  |  |  |  |  |
Forward starting interest rate swap settlement amount |  |  | 9,000,000 |  |  |  |  |  |  |  |  |  |
Percentage of interest in Millennium |  |  | 47.50% |  |  |  |  |  |  |  |  | 47.50% |
Loss recognized in income statement classified in accumulated other comprehensive income(loss) |  |  | 0 |  |  |  |  |  |  |  |  |  |
Cash on deposit with brokers for margin requirements |  |  | 27,700,000 |  | 45,700,000 |  |  |  |  |  |  |  |
Interest rate on debt |  |  |  |  |  |  |  |  |  | 5.25% | 5.45% |  |
Debt Instrument, Interest Rate, Effective Percentage |  |  |  |  |  |  |  |  |  | 5.67% | 5.88% |  |
Other Comprehensive Income Unrecognized Gain Loss On Derivatives Arising During Period Net Of Tax |  |  |  |  |  |  |  |  |  |  |  | $ 18,200,000 | $ 18,700,000

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- Definition Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669686-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e637-108580 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e681-108580 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669646-108580 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=7668309&loc=d3e80784-113994 + Details
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