Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income	$ 4,101	$ 3,711	$ 2,728
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	1,842	1,690	1,720
Lower of cost or market inventory valuation adjustment	790	0	0
Aruba Refinery asset retirement expense and other	0	63	0
Gain on disposition of retained interest in CST Brands, Inc.	0	0	(325)
Deferred income tax expense	165	445	501
Changes in current assets and current liabilities	(1,306)	(1,810)	922
Changes in deferred charges and credits and other operating activities, net	19	142	18
Net cash provided by operating activities	5,611	4,241	5,564
Cash flows from investing activities:
Capital expenditures	(1,618)	(2,153)	(2,121)
Deferred turnaround and catalyst costs	(673)	(649)	(634)
Investments in joint ventures	(141)	(14)	(76)
Other investing activities, net	(55)	(28)	19
Net cash used in investing activities	(2,487)	(2,844)	(2,812)
Cash flows from financing activities:
Proceeds from debt issuances or borrowings	1,446	28	0
Repayments of debt and capital lease obligations	(513)	(204)	(486)
Proceeds from the exercise of stock options	34	47	59
Purchase of common stock for treasury	(2,838)	(1,296)	(928)
Common stock dividends	(848)	(554)	(462)
Net proceeds from issuance of Valero Energy Partners LP common units	189	0	369
Contributions from noncontrolling interests	5	12	45
Distributions to noncontrolling interests (public unitholders) of Valero Energy Partners LP	(20)	(12)	0
Distribution to other noncontrolling interest	(25)	0	0
Disposition of retail business:
Proceeds from short-term debt in anticipation of separation	0	0	550
Cash distributed to Valero by CST Brands, Inc.	0	0	500
Cash held and retained by CST Brands, Inc. upon separation	0	0	(315)
Proceeds from short-term debt related to disposition of retained interest	0	0	525
Repayments of short-term debt related to disposition of retained interest	0	0	(58)
Other financing activities, net	25	49	38
Net cash used in financing activities	(2,545)	(1,930)	(163)
Effect of foreign exchange rate changes on cash	(154)	(70)	(20)
Net increase (decrease) in cash and temporary cash investments	425	(603)	2,569
Cash and temporary cash investments at beginning of year	3,689	4,292	1,723
Cash and temporary cash investments at end of year	$ 4,114	$ 3,689	$ 4,292