Discontinued Operations (Narrative) (Details) (USD $) In Millions	3 Months Ended	9 Months Ended															3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2011	Dec. 31, 2010	Dec. 31, 2010 Conectiv Energy [Member] Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]	Sep. 30, 2011 Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]		Dec. 31, 2010 Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]		Dec. 31, 2010 Conectiv Energy [Member] Significant Other Observable Inputs (Level 2) [Member]	Sep. 30, 2011 Significant Other Observable Inputs (Level 2) [Member]		Dec. 31, 2010 Significant Other Observable Inputs (Level 2) [Member]		Dec. 31, 2010 Conectiv Energy [Member] Significant Unobservable Inputs (Level 3) [Member]	Sep. 30, 2011 Significant Unobservable Inputs (Level 3) [Member]	Dec. 31, 2010 Significant Unobservable Inputs (Level 3) [Member]	Sep. 30, 2011 Conectiv Energy [Member]	Sep. 30, 2010 Conectiv Energy [Member]	Sep. 30, 2010 Conectiv Energy [Member]	Dec. 31, 2010 Conectiv Energy [Member]	Jun. 30, 2010 Calpine Corporation [Member]	Sep. 30, 2010 Calpine Corporation [Member]
Net Assets																	$ 2			$ 45
Accounts receivable, less allowance for uncollectible accounts																				81
Inventories																				20
Adjustments to remaining miscellaneous assets and liabilities	0	4
Net derivative liabilities																				(18)
Derivative instruments, assets	198	198	114		131	[1]	26	[1]	4	48	[1]	69	[1]	3	19	19				7
Derivative instruments, liabilities	137	137	216	10	46	[1]	75	[1]	80	72	[1]	118	[1]		19	23				90
After-tax income related to the sale of tolling agreement	1
Expense incurred in connection with a financial transaction		1
Net losses from dispositions of assets and businesses of discontinued operations, net of income taxes																		(2)	128		67	73
Employee severance and retention benefits																					9
After-tax accrued expenses																					12
Losses on assets not sold																						27
Unrealized loss recognized on energy contracts																					(50)
Tax charges aggregated to valuation allowances																					28	28
Payments against fair value of derivative																	82
Administrative fee, after-tax																	$ 1

[1] There were no significant transfers of instruments between level 1 and level 2 valuation categories.