Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net income	$ 513	$ 968
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	485	441
Lower of cost or market inventory valuation adjustment	(293)	0
Deferred income tax expense (benefit)	121	(61)
Changes in current assets and current liabilities	(177)	57
Changes in deferred charges and credits and other operating activities, net	(9)	28
Net cash provided by operating activities	640	1,433
Cash flows from investing activities:
Capital expenditures	(316)	(458)
Deferred turnaround and catalyst costs	(161)	(240)
Other investing activities, net	(4)	(15)
Net cash used in investing activities	(481)	(713)
Cash flows from financing activities:
Proceeds from debt issuances or borrowings	0	1,446
Repayments of debt and capital lease obligations	(3)	(403)
Proceeds from the exercise of stock options	3	15
Purchase of common stock for treasury	(265)	(325)
Common stock dividends	(282)	(206)
Distributions to noncontrolling interests (public unitholders) of Valero Energy Partners LP	(7)	(5)
Other financing activities, net	10	4
Net cash provided by (used in) financing activities	(544)	526
Effect of foreign exchange rate changes on cash	49	(65)
Net increase (decrease) in cash and temporary cash investments	(336)	1,181
Cash and temporary cash investments at beginning of period	4,114	3,689
Cash and temporary cash investments at end of period	$ 3,778	$ 4,870