Employee Benefit Plans (Net Periodic Benefit (Credit) Cost and Amounts Recognized in Other Comprehensive Income and Regulatory Assets and Liabilities) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	$ (509)		$ (519)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	116		108		102
Interest cost	268		258		266
Expected return on plan assets	(430)		(440)		(410)
Amortization of prior service (credit) cost	3		3		3
Amortization of net actuarial loss	132		96		59
Settlements and curtailments	0	[1]	0	[1]	136	[1]
Special termination benefits	0	[2]	0	[2]	(10)	[2]
Net periodic benefit (credit) cost	89		25		166
Changes in plan assets and benefit obligations recognized in other comprehensive income and regulatory assets and liabilities:
Current year net actuarial (gain) loss	786		534		95
Prior service (credit) cost	0		0		1
Settlements and curtailments	0	[1]	0	[1]	(50)	[1]
Amortization of net actuarial loss	(132)		(96)		(59)
Amortization of prior service credit (cost)	3		3		3
Total recognized in other comprehensive income and regulatory assets and liabilities	651		435		(16)
Significant assumptions used to determine periodic cost:
Discount rate	5.50%		5.90%		6.60%
Expected long-term rate of return on plan assets	8.50%		8.50%		8.50%
Weighted average rate of increase for compensation	4.21%		4.61%		4.76%
Other Postretirement Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	44		48		56
Interest cost	79		94		101
Expected return on plan assets	(79)		(79)		(69)
Amortization of prior service (credit) cost	(13)		(13)		(7)
Amortization of net actuarial loss	6		12		12
Settlements and curtailments	(4)	[1]	1	[1]	37	[1]
Special termination benefits	0	[2]	0	[2]	(1)	[2]
Net periodic benefit (credit) cost	33		63		131
Changes in plan assets and benefit obligations recognized in other comprehensive income and regulatory assets and liabilities:
Current year net actuarial (gain) loss	139		(157)		13
Prior service (credit) cost	1		(70)		0
Settlements and curtailments	(2)	[1]	(1)	[1]	(1)	[1]
Amortization of net actuarial loss	(6)		(12)		(12)
Amortization of prior service credit (cost)	(13)		(13)		(7)
Total recognized in other comprehensive income and regulatory assets and liabilities	$ 145		$ (227)		$ 7
Significant assumptions used to determine periodic cost:
Discount rate	5.50%		5.90%		6.60%
Expected long-term rate of return on plan assets	7.75%		7.75%		7.75%
Weighted average rate of increase for compensation	4.22%		4.62%		4.79%
Healthcare cost trend rate	7.00%	[3]	7.00%	[3]	7.00%	[3]
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	4.60%	[3]	4.60%	[3]	4.60%	[3]
Year that the rate reaches the ultimate trend rate	2061	[3]	2060	[3]	2060	[3]

[1] 2012 amounts relate to the sale of Salem Harbor. 2010 amounts relate to the sales of Peoples and Dominion's Appalachian E&P operations and a workforce reduction program.

[2] Represents a one-time special termination benefit for certain employees in connection with a workforce reduction program.

[3] Assumptions used to determine periodic cost for the following year.