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Fair Value Of Financial Instruments (Fair Value, Assets Measured On Recurring Basis, Unobservable Input Reconciliation) (Detail) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 9 Months Ended | ||||
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Sep. 30, 2012
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Sep. 30, 2011
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Jun. 30, 2011
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Sep. 30, 2012
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Sep. 30, 2011
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Sep. 30, 2012
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| Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Roll Forward] | ||||||
| Balance | $ 83.9 | $ 64.0 | $ 157.9 | $ 45.6 | ||
| Total gains | ||||||
| Included in earnings | 24.9 | 53.8 | 129.6 | 144.9 | ||
| Included in other comprehensive income | 0 | 0 | 0 | 0 | ||
| Settlements | (52.9) | (50.0) | (231.6) | (102.7) | ||
| Transfers into Level 3 | 0 | 0 | 0 | 0 | ||
| Transfers out of Level 3 | 0 | 0 | (20.0) | 0 | (20.0) | |
| Balance | 55.9 | 67.8 | 64.0 | 55.9 | 67.8 | |
| Total gains for the period included in earnings attributable to the change in unrealized gains on assets still held at the reporting date | 24.9 | 53.8 | 129.6 | 144.9 | ||
| Asset retirement obligation at beginning of period | $ 194.9 | $ 162.1 | $ 208.3 | |||
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- Details
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- Definition
The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
This item represents the amount of the total change in unrealized (holding) gains or losses for the period which are included in the statement of income (or changes in net assets) in trading revenues. Such unrealized (holding) gains or losses relate to those assets still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Amount of gain (loss) recognized in earnings, arising from assets measured at fair value on a recurring basis using unobservable inputs (level 3). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of gain (loss) recognized in other comprehensive income, arising from assets measured at fair value on a recurring basis using unobservable inputs (level 3). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Settlements that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Transfers into assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Transfers out of assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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