Discontinued Operations (Narrative) (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Adjustments to remaining miscellaneous assets and liabilities	$ 4		$ 4
Derivative instruments, assets	153		153		114
Derivative instruments, liabilities	153		153		216
After-tax income related to the sale of tolling agreement	1
Expense incurred in connection with a financial transaction			1
Loss on disposal of asset related to discontinued operation, net of tax		132		130
Conectiv Energy [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]
Derivative instruments, liabilities					10
Conectiv Energy [Member] | Significant Other Observable Inputs (Level 2) [Member]
Derivative instruments, assets					4
Derivative instruments, liabilities					80
Conectiv Energy [Member] | Significant Unobservable Inputs (Level 3) [Member]
Derivative instruments, assets					3
Conectiv Energy [Member]
Net Assets	2		2		45
Accounts receivable, less allowance for uncollectible accounts					81
Inventories					20
Net Derivative (Liability) Asset					18
Derivative instruments, assets					7
Derivative instruments, liabilities					90
Net losses from dispositions of assets and businesses of discontinued operations, net of income taxes	(1)	132		130
Payments against fair value of derivative	82		82
Administrative fee, after-tax	1		1
Calpine Corporation [Member]
Net losses from dispositions of assets and businesses of discontinued operations, net of income taxes		67		67
Employee severance and retention benefits	9
After-tax accrued expenses	13		13
Losses on assets not sold		51		49
Unrealized loss recognized on energy contracts		(50)
Tax charges aggregated to valuation allowances		$ 14		$ 14