Employee Benefit Plans (Pension Plan and Other Postretirement Benefit Plan Obligations and Plan Assets and Includes a Statement of the Plans Funded Status) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Jun. 30, 2013
Changes in fair value of plan assets:
Actual return on plan assets	$ 706		$ 959
Employer contributions	41		40		40
Dominion Gas Holdings, LLC
Changes in fair value of plan assets:
Actual return on plan assets	157		214
Employer contributions	7		7		6
Pension Benefits
Changes in benefit obligation:
Benefit obligation at beginning of year	5,625		6,125
Service cost	114		131		116
Interest cost	290		271		268
Benefits paid	(236)		(229)
Actuarial (gains) losses during the year	887		(650)
Plan amendments	0	[1]	1	[1]
Settlements and curtailments	(13)	[2]	(24)	[2]
Special termination benefits	0		0		0
Medicare Part D reimbursement	0		0
Benefit obligation at end of year	6,667		5,625		6,125
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	6,113		5,553
Actual return on plan assets	601		781
Employer contributions	15		8
Benefits paid	(236)		(229)
Settlements	(13)	[2]	0	[2]
Fair value of plan assets at end of year	6,480		6,113		5,553
Funded status at end of year	(187)		488
Noncurrent pension and other postretirement benefit assets	946		913
Other current liabilities	(13)		(15)
Noncurrent pension and other postretirement benefit liabilities	(1,120)		(410)
Net amount recognized	(187)		488
Discount rate	5.30%					4.80%
Weighted average rate of increase for compensation	4.22%		4.21%
Expected long-term rate of return on plan assets	8.75%		8.50%		8.50%
Pension Benefits | Gas Union Plans
Changes in fair value of plan assets:
Discount rate	5.20%
Pension Benefits | Minimum
Changes in fair value of plan assets:
Discount rate	4.40%	[3]	5.20%	[3]
Pension Benefits | Maximum
Changes in fair value of plan assets:
Discount rate			5.30%	[3]
Pension Benefits | Dominion Gas Holdings, LLC
Changes in benefit obligation:
Benefit obligation at beginning of year	563		607
Service cost	12		13		11
Interest cost	28		27		28
Benefits paid	(29)		(27)
Actuarial (gains) losses during the year	64		(57)
Plan amendments	0		0
Medicare Part D reimbursement	0		0
Benefit obligation at end of year	638		563		607
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	1,403		1,254
Actual return on plan assets	136		176
Employer contributions	0		0
Benefits paid	(29)		(27)
Fair value of plan assets at end of year	1,510		1,403		1,254
Funded status at end of year	872		840
Noncurrent pension and other postretirement benefit assets	872		840
Noncurrent pension and other postretirement benefit liabilities	0	[4]	0	[4]
Net amount recognized	872		840
Discount rate	4.40%		5.20%
Weighted average rate of increase for compensation	3.93%		3.93%
Expected long-term rate of return on plan assets	8.75%		8.50%		8.50%
Other Postretirement Benefits
Changes in benefit obligation:
Benefit obligation at beginning of year	1,360		1,719
Service cost	32		43		44
Interest cost	67		73		79
Benefits paid	(78)		(75)
Actuarial (gains) losses during the year	177		(170)
Plan amendments	9	[1]	(220)	[1]
Settlements and curtailments	0	[2]	(16)	[2]
Special termination benefits	0		1		0
Medicare Part D reimbursement	4		5
Benefit obligation at end of year	1,571		1,360		1,719
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	1,315		1,156
Actual return on plan assets	105		178
Employer contributions	12		12
Benefits paid	(30)		(31)
Settlements	0	[2]	0	[2]
Fair value of plan assets at end of year	1,402		1,315		1,156
Funded status at end of year	(169)		(45)
Noncurrent pension and other postretirement benefit assets	10		29
Other current liabilities	(3)		(3)
Noncurrent pension and other postretirement benefit liabilities	(176)		(71)
Net amount recognized	(169)		(45)
Discount rate	5.10%		4.80%			4.70%
Weighted average rate of increase for compensation	4.22%		4.22%
Expected long-term rate of return on plan assets	8.50%		7.75%		7.75%
Other Postretirement Benefits | Gas Union Plans
Changes in fair value of plan assets:
Discount rate	5.00%
Other Postretirement Benefits | Minimum
Changes in fair value of plan assets:
Discount rate	4.40%	[3]	5.00%	[3]
Expected long-term rate of return on plan assets	7.75%
Other Postretirement Benefits | Maximum
Changes in fair value of plan assets:
Discount rate			5.10%	[3]
Expected long-term rate of return on plan assets	8.50%
Other Postretirement Benefits | Dominion Gas Holdings, LLC
Changes in benefit obligation:
Benefit obligation at beginning of year	269		287
Service cost	6		7		7
Interest cost	13		12		14
Benefits paid	(16)		(17)
Actuarial (gains) losses during the year	38		(21)
Plan amendments	9		0
Medicare Part D reimbursement	1		1
Benefit obligation at end of year	320		269		287
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	273		242
Actual return on plan assets	21		38
Employer contributions	10		10
Benefits paid	(16)		(17)
Fair value of plan assets at end of year	288		273		242
Funded status at end of year	(32)		4
Noncurrent pension and other postretirement benefit assets	0		19
Noncurrent pension and other postretirement benefit liabilities	(32)	[4]	(15)	[4]
Net amount recognized	$ (32)		$ 4
Discount rate	4.40%		5.00%
Weighted average rate of increase for compensation	3.93%		3.93%
Expected long-term rate of return on plan assets	8.50%		7.75%		7.75%

[1] 2013 other postretirement benefits amount relates to a plan amendment that changed medical coverage for certain Medicare-eligible retirees.

[2] 2014 amounts relate primarily to a settlement charge for certain executives. 2013 amounts relate primarily to the decommissioning of Kewaunee.

[3] 2013 pension and other postretirement benefits discount rates: 5.20% and 5.00% for the gas union plans and 5.30% and 5.10% for the nonunion and other union plans, respectively.

[4] Reflected in other deferred credits and other liabilities in Dominion Gas' Consolidated Balance Sheets.