Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net income	$ 1,356	$ 2,333
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	956	866
Lower of cost or market inventory valuation adjustment	(747)	0
Asset impairment loss	56	0
Deferred income tax expense (benefit)	195	(82)
Changes in current assets and current liabilities	1,130	615
Changes in deferred charges and credits and other operating activities, net	13	30
Net cash provided by operating activities	2,959	3,762
Cash flows from investing activities:
Capital expenditures	(610)	(828)
Deferred turnaround and catalyst costs	(325)	(400)
Other investing activities, net	4	14
Net cash used in investing activities	(931)	(1,214)
Cash flows from financing activities:
Proceeds from debt issuances or borrowings	197	1,446
Repayments of debt and capital lease obligations	(24)	(479)
Proceeds from the exercise of stock options	3	20
Purchase of common stock for treasury	(665)	(992)
Common stock dividends	(564)	(409)
Distributions to noncontrolling interests (public unitholders) of Valero Energy Partners LP	(14)	(9)
Distributions to other noncontrolling interest	(33)	(25)
Other financing activities, net	(137)	16
Net cash used in financing activities	(1,237)	(432)
Effect of foreign exchange rate changes on cash	20	(41)
Net increase in cash and temporary cash investments	811	2,075
Cash and temporary cash investments at beginning of period	4,114	3,689
Cash and temporary cash investments at end of period	$ 4,925	$ 5,764