|
Use of Collateral (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2013
|
Dec. 31, 2012
|
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Use of Collateral [Abstract] | ||||||||||
| Margin Deposit Assets | $ 261 | [1] | $ 196 | [1] | ||||||
| Natural gas and power prepayments | 28 | 35 | ||||||||
| Total margin deposits and natural gas and power prepayments with our counterparties | 289 | [2] | 231 | [2] | ||||||
| Letters of credit issued | 488 | 484 | ||||||||
| First priority liens under power and natural gas agreements | 31 | 14 | ||||||||
| First priority liens under interest rate swap agreements | 132 | 206 | ||||||||
| Total letters of credit and first priority liens with our counterparties | 651 | 704 | ||||||||
| Security Deposit Liability | 5 | [1],[3] | 11 | [1],[3] | ||||||
| Letters of credit posted with us by our counterparties | 2 | 1 | ||||||||
| Total margin deposits and letters of credit posted with us by our counterparties | 7 | 12 | ||||||||
| Use of Collateral (Textuals) [Abstract] | ||||||||||
| Margin And Prepayment Amounts Included In Other Assets | 17 | 20 | ||||||||
| Margin And Prepayment Amounts Included In Margin Deposits And Other Prepaid Expenses | $ 272 | $ 211 | ||||||||
|
||||||||||