Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified | 9 Months Ended | ||
|---|---|---|---|
Sep. 30, 2011 | Dec. 31, 2010 | Jul. 02, 2010 | |
| Commitments and Contingencies [Abstract] | |||
| Environmental remediation liabilities related to Acquisition | $ 0 | ||
| Amount of expenditures over which PHI is responsible for related to the Conectiv Acquisition | $ 10 | ||
| Amount of shares remaining in reserve for distribution to holders of disputed claims | 21 | ||
| Amount of shares authorized to settle unsecured claims | 485 | ||
| Commitments and Contingencies [Line Items] | |||
| Power generation capacity (in Megawatts) | 11,372 | 13,553 |