Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 2,784	$ 3,353	$ 4,156
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	2,255	2,069	1,986
Deferred income tax expense (benefit)	234	203	(2,543)
Changes in current assets and current liabilities	294	(1,297)	1,289
Changes in deferred charges and credits and other operating activities, net	(36)	43	594
Net cash provided by operating activities	5,531	4,371	5,482
Cash flows from investing activities:
Investments in unconsolidated joint ventures	(164)	(181)	(406)
Peru Acquisition, net of cash acquired	0	(468)	0
Acquisitions of undivided interests	(72)	(212)	(72)
Other investing activities, net	12	8	(2)
Net cash provided by (used in) investing activities	(3,001)	(3,928)	(2,382)
Cash flows from financing activities:
Purchases of common stock for treasury	(777)	(1,708)	(1,372)
Common stock dividends	(1,492)	(1,369)	(1,242)
Acquisition of Valero Energy Partners LP publicly held common units	(950)	0	0
Contributions from noncontrolling interests	0	32	30
Distributions to noncontrolling interests	(70)	(116)	(67)
Other financing activities, net	(28)	(15)	20
Net cash provided by (used in) financing activities	(2,997)	(3,168)	(2,272)
Effect of foreign exchange rate changes on cash	68	(143)	206
Net increase (decrease) in cash and cash equivalents	(399)	(2,868)	1,034
Cash and cash equivalents at beginning of year	2,982	5,850	4,816
Cash and cash equivalents at end of year	2,583	2,982	5,850
Minor Acquisitions [Member]
Cash flows from investing activities:
Asset acquisitions	0	(88)	0
Ethanol Plants [Member]
Cash flows from investing activities:
Asset acquisitions	(3)	(320)	0
Variable Interest Entities (VIEs) [Member]
Cash flows from financing activities:
Proceeds from debt issuances and borrowings	239	109	0
Repayments of debt and finance lease obligations	(6)	(6)	(6)
Diamond Green Diesel Holdings LLC (DGD) [Member]
Cash flows from investing activities:
Capital expenditures	(142)	(165)	(84)
Deferred turnaround and catalyst cost expenditures	(18)	(27)	(4)
Other VIEs [Member]
Cash flows from investing activities:
Capital expenditures	(225)	(124)	(26)
Excluding Variable Interest Entities (VIEs) [Member]
Cash flows from investing activities:
Capital expenditures	(1,627)	(1,463)	(1,269)
Deferred turnaround and catalyst cost expenditures	(762)	(888)	(519)
Cash flows from financing activities:
Proceeds from debt issuances and borrowings	1,892	1,258	380
Repayments of debt and finance lease obligations	$ (1,805)	$ (1,353)	$ (15)