Environmental Matters (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended										3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011		Mar. 31, 2012 MGP And Other Sites		Mar. 31, 2011 MGP And Other Sites		Mar. 31, 2012 MGP And Other Sites PEC	Dec. 31, 2011 MGP And Other Sites PEC	Mar. 31, 2012 Remediation Of Distribution And Substation Transformers		Mar. 31, 2011 Remediation Of Distribution And Substation Transformers		Mar. 31, 2012 Orlando MGP OU1 PEF
Disclosure Environmental Matters Details [Line Items]
Beginning Balance	$ 23		$ 35		$ 17		$ 20				$ 6		$ 15
Amount accrued for environmental loss contingencies	5		0		3		0				2		0
Expenditures for environmental loss contingencies	(4)		(6)		(2)		(1)				(2)		(5)
Ending Balance	24	[1]	29	[1]	18	[1]	19	[1]			6	[1]	10	[1]
Period expected to be paid out over	one to 12 years		one to 12 years
(Ward) site recorded liability									5	5
Site contingency, loss exposure not accrued									6
Site contingency, loss exposure not accrued, reimbursement									1
Site contingency, loss exposure in excess of accrual, high estimate															$ 4

[1] Expected to be paid out over one to 12 years.