Severance (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012
Severance [Line Items]
Number of employees that accepted the termination benefits		650
Severance charges	$ 66	$ 66
Restructuring Liability, Beginning Balance		5
Provision/Adjustments		53
Cash Reductions		(15)
Restructuring Liability, Ending Balance	43	43
Duke Energy [Member]
Severance [Line Items]
Number of employees that accepted the termination benefits		1,100
Minimum [Member] | Duke Energy [Member]
Severance [Line Items]
Estimated future severance costs		80
Maximum [Member] | Duke Energy [Member]
Severance [Line Items]
Estimated future severance costs		110
PEC [Member]
Severance [Line Items]
Severance charges	42	42
Restructuring Liability, Beginning Balance		5
Provision/Adjustments		26
Cash Reductions		(7)
Restructuring Liability, Ending Balance	24	24
PEF [Member]
Severance [Line Items]
Severance charges	24	24
Restructuring Liability, Beginning Balance		0
Provision/Adjustments		10
Cash Reductions		(3)
Restructuring Liability, Ending Balance	$ 7	$ 7