Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income	$ 815	$ 1,457
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	1,117	1,021
Deferred income tax benefit	(12)	(24)
Changes in current assets and current liabilities	413	(445)
Changes in deferred charges and credits and other operating activities, net	61	188
Net cash provided by operating activities	2,394	2,197
Cash flows from investing activities:
Deferred turnaround and catalyst costs	(471)	(490)
Investments in joint ventures	(90)	(119)
Peru Acquisition, net of cash acquired	0	(471)
Acquisitions of undivided interests	(29)	(145)
Minor acquisitions		(91)
Other investing activities, net	9	2
Net cash provided by (used in) investing activities	(1,555)	(2,132)
Cash flows from financing activities:
Repayments of debt and finance lease obligations	(1,789)	(1,345)
Purchases of common stock for treasury	(248)	(647)
Common stock dividends	(751)	(690)
Acquisition of Valero Energy Partners LP publicly held common units	(950)	0
Contributions from noncontrolling interests	0	32
Distributions to noncontrolling interests	(18)	(50)
Other financing activities, net	(31)	(16)
Net cash used in financing activities	(1,825)	(1,402)
Effect of foreign exchange rate changes on cash	37	(62)
Net increase (decrease) in cash and cash equivalents	(949)	(1,399)
Cash and cash equivalents at beginning of period	2,982	5,850
Cash and cash equivalents at end of period	2,033	4,451
Certain Variable Interest Entities (VIEs) [Member]
Cash flows from investing activities:
Capital expenditures	(69)	(78)
Cash flows from financing activities:
Proceeds from debt issuances and borrowings	70	56
Excluding Certain Variable Interest Entities (VIEs) [Member]
Cash flows from investing activities:
Capital expenditures	(905)	(740)
Cash flows from financing activities:
Proceeds from debt issuances and borrowings	1,892	1,258
Minor Acquisitions [Member]
Cash flows from investing activities:
Minor acquisitions	$ 0	$ (91)