Equity (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		0 Months Ended	1 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Apr. 30, 2015	Apr. 30, 2015
Reconciliation of the Beginning and Ending Balances of the Carrying Amounts of Equity
Balance as of beginning of period	$ 21,244	$ 19,946
Net income	968	836
Dividends	(206)	(133)
Stock-based compensation expense	9	10
Tax deduction in excess of stock-based compensation expense	15	25
Transactions in connection with stock-based compensation plans:
Stock issuances	15	24
Contributions from noncontrolling interests	2	0
Distributions to public unitholders of Valero Energy Partners LP	(5)	(1)
Other comprehensive loss	(363)	(73)
Balance as of end of period	21,342	20,408
Dividend Declared [Member] | Subsequent Event [Member]
Equity (Textual)
Dividends payable, date declared			Apr. 30, 2015
Dividends payable, amount per share			$ 0.40	$ 0.40
Dividends payable, date to be paid			Jun. 10, 2015
Dividends payable, date of record			May 13, 2015
Stock-Based Compensation Plans Repurchase Program [Member]
Transactions in connection with stock-based compensation plans:
Stock repurchases	(50)	(17)
Equity (Textual)
Stock repurchases	50	17
Common Stock Repurchase Program [Member]
Transactions in connection with stock-based compensation plans:
Stock repurchases	(287)	(209)
Equity (Textual)
Stock repurchases	287	209
Treasury Stock [Member] | Subsequent Event [Member]
Transactions in connection with stock-based compensation plans:
Stock repurchases				(104)
Equity (Textual)
Stock repurchases, in shares				1.7
Stock repurchases				104
Treasury Stock [Member] | Stock-Based Compensation Plans Repurchase Program [Member]
Equity (Textual)
Stock repurchases, in shares	1.0	0
Treasury Stock [Member] | Common Stock Repurchase Program [Member]
Equity (Textual)
Stock repurchases, in shares	5.0	4.0
Treasury Stock [Member] | Common Stock Repurchase Program [Member] | Subsequent Event [Member]
Transactions in connection with stock-based compensation plans:
Stock repurchases				(76)
Equity (Textual)
Stock repurchases				76
Parent [Member]
Reconciliation of the Beginning and Ending Balances of the Carrying Amounts of Equity
Balance as of beginning of period	20,677	19,460
Net income	964	828
Dividends	(206)	(133)
Stock-based compensation expense	9	10
Tax deduction in excess of stock-based compensation expense	15	25
Transactions in connection with stock-based compensation plans:
Stock issuances	15	24
Contributions from noncontrolling interests	0	0
Distributions to public unitholders of Valero Energy Partners LP	0	0
Other comprehensive loss	(363)	(73)
Balance as of end of period	20,774	19,915
Parent [Member] | Stock-Based Compensation Plans Repurchase Program [Member]
Transactions in connection with stock-based compensation plans:
Stock repurchases	(50)	(17)
Equity (Textual)
Stock repurchases	50	17
Parent [Member] | Common Stock Repurchase Program [Member]
Transactions in connection with stock-based compensation plans:
Stock repurchases	(287)	(209)
Equity (Textual)
Stock repurchases	287	209
Noncontrolling Interest [Member]
Reconciliation of the Beginning and Ending Balances of the Carrying Amounts of Equity
Balance as of beginning of period	567	486
Net income	4	8
Transactions in connection with stock-based compensation plans:
Contributions from noncontrolling interests	2	0
Distributions to public unitholders of Valero Energy Partners LP	(5)	(1)
Other comprehensive loss	0	0
Balance as of end of period	$ 568	$ 493