Employee Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Remeasurement due to plan amendments	$ 371
Changes in plan assets (a):
Fair value of plan assets at beginning of year	1,729
Fair value of plan assets at end of year	1,909	1,729
Defined Benefit Plan, Assets for Plan Benefits
Accrued expenses	(30)	(32)
Other long-term liabilities	(507)	(982)
Employee Benefit Plans (Textual)
Contributions to defined contribution plans	62	61	59
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Remeasurement due to plan amendments	328	0	0
Initial effect of defined benefit plan amendment	(328)
Changes in benefit obligation:
Benefit obligation at beginning of year	2,307	1,881
Service cost	137	140	104
Interest cost	86	93	85
Participant contributions	0	0
Plan amendments	(274)	9
Curtailment gain	(6)	(16)
Benefits paid	(170)	(90)
Actuarial (gain) loss	(169)	289
Other	3	1
Benefit obligation at end of year	1,914	2,307	1,881
Changes in plan assets (a):
Fair value of plan assets at beginning of year	1,729	1,487
Actual return on plan assets	306	167
Valero contributions	41	164
Participant contributions	0	0
Benefits paid	(170)	(90)
Other	3	1
Fair value of plan assets at end of year	1,909	1,729	1,487
Reconciliation of funded status (a):
Funded status at end of year	(5)	(578)
Accumulated benefit obligation	1,811	1,857
Defined Benefit Plan, Assets for Plan Benefits
Deferred charges and other assets, net	208	0
Accrued expenses	(11)	(11)
Other long-term liabilities	(202)	(567)
Defined benefit plan, amounts recognized in balance sheet, total	(5)	(578)
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Remeasurement due to plan amendments	43	0	0
Initial effect of defined benefit plan amendment	(43)
Changes in benefit obligation:
Benefit obligation at beginning of year	436	438
Service cost	12	12	11
Interest cost	18	21	22
Participant contributions	15	14
Plan amendments	(43)	0
Curtailment gain	0	0
Benefits paid	(37)	(35)
Actuarial (gain) loss	(77)	(17)
Other	0	3
Benefit obligation at end of year	324	436	438
Changes in plan assets (a):
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Valero contributions	19	19
Participant contributions	15	14
Benefits paid	(37)	(35)
Other	3	2
Fair value of plan assets at end of year	0	0	0
Reconciliation of funded status (a):
Funded status at end of year	(324)	(436)
Defined Benefit Plan, Assets for Plan Benefits
Deferred charges and other assets, net	0	0
Accrued expenses	(19)	(21)
Other long-term liabilities	(305)	(415)
Defined benefit plan, amounts recognized in balance sheet, total	$ (324)	$ (436)