|
Financial and Other Derivative Instruments (Details) (USD $)
In Millions, unless otherwise specified
|
Sep. 30, 2012
|
Dec. 31, 2011
|
| Derivatives designated as hedging instruments: |
|
|
| Derivative Asset Fair Value Gross Asset |
$ 1,444 |
$ 2,805 |
| Derivative Liability Fair Value Gross Liability |
(1,435) |
(2,811) |
| Derivative Assets, Current |
123 |
222 |
| Derivative Assets, Noncurrent |
63 |
74 |
| Derivative Liabilities, Current |
146 |
158 |
| Derivative Liabilities, Noncurrent |
30 |
89 |
|
Estimate of Fair Value, Fair Value Disclosure [Member]
|
|
|
| Derivatives designated as hedging instruments: |
|
|
| Derivative Assets, Current |
1,161 |
2,272 |
| Derivative Assets, Noncurrent |
283 |
533 |
| Derivative Liabilities, Current |
(1,185) |
(2,282) |
| Derivative Liabilities, Noncurrent |
(250) |
(529) |
|
Derivative Asset [Member]
|
|
|
| Derivatives designated as hedging instruments: |
|
|
| Derivative Assets, Current |
1,161 |
2,272 |
| Derivative Assets, Noncurrent |
283 |
533 |
|
Derivative Liabilities [Member]
|
|
|
| Derivatives designated as hedging instruments: |
|
|
| Derivative Liabilities, Current |
(1,185) |
(2,282) |
| Derivative Liabilities, Noncurrent |
(250) |
(529) |
|
Counterparty Netting [Member]
|
|
|
| Derivatives designated as hedging instruments: |
|
|
| Derivative Assets, Current |
(1,038) |
(2,050) |
| Derivative Assets, Noncurrent |
(220) |
(440) |
| Derivative Liabilities, Current |
1,038 |
2,050 |
| Derivative Liabilities, Noncurrent |
220 |
440 |
|
Collateral Adjustment [Member]
|
|
|
| Derivatives designated as hedging instruments: |
|
|
| Derivative Assets, Current |
0 |
0 |
| Derivative Assets, Noncurrent |
0 |
(19) |
| Derivative Liabilities, Current |
1 |
74 |
| Derivative Liabilities, Noncurrent |
0 |
0 |
|
Derivative [Member]
|
|
|
| Derivatives designated as hedging instruments: |
|
|
| Derivative Assets, Current |
123 |
222 |
| Derivative Assets, Noncurrent |
63 |
74 |
| Derivative Liabilities, Current |
(146) |
(158) |
| Derivative Liabilities, Noncurrent |
(30) |
(89) |
|
Designated as Hedging Instrument [Member] | Interest rate contracts [Member]
|
|
|
| Derivatives designated as hedging instruments: |
|
|
| Derivative Asset Fair Value Gross Asset |
0 |
0 |
| Derivative Liability Fair Value Gross Liability |
(1) |
(1) |
|
Not Designated as Hedging Instrument [Member]
|
|
|
| Derivatives designated as hedging instruments: |
|
|
| Derivative Asset Fair Value Gross Asset |
1,444 |
2,805 |
| Derivative Liability Fair Value Gross Liability |
(1,434) |
(2,810) |
|
Not Designated as Hedging Instrument [Member] | Foreign currency exchange contracts [Member]
|
|
|
| Derivatives designated as hedging instruments: |
|
|
| Derivative Asset Fair Value Gross Asset |
1 |
3 |
| Derivative Liability Fair Value Gross Liability |
(2) |
(5) |
|
Not Designated as Hedging Instrument [Member] | Natural Gas [Member]
|
|
|
| Derivatives designated as hedging instruments: |
|
|
| Derivative Asset Fair Value Gross Asset |
959 |
2,024 |
| Derivative Liability Fair Value Gross Liability |
(975) |
(2,080) |
|
Not Designated as Hedging Instrument [Member] | Electricity [Member]
|
|
|
| Derivatives designated as hedging instruments: |
|
|
| Derivative Asset Fair Value Gross Asset |
431 |
747 |
| Derivative Liability Fair Value Gross Liability |
(419) |
(705) |
|
Not Designated as Hedging Instrument [Member] | Other Credit Derivatives [Member]
|
|
|
| Derivatives designated as hedging instruments: |
|
|
| Derivative Asset Fair Value Gross Asset |
53 |
31 |
| Derivative Liability Fair Value Gross Liability |
$ (38) |
$ (20) |