Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended												12 Months Ended
		Dec. 31, 2017		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Quarterly Financial Data
Operating revenues		$ 26,392	[1]	$ 23,562	$ 22,254	$ 21,772	$ 20,712	$ 19,649	[2]	$ 19,584	[3]	$ 15,714	[4]	$ 93,980	[5]	$ 75,659	[5]	$ 87,804	[5]
Gross profit	[6]	1,121	[1]	1,624	1,063	739	841	1,096	[2]	1,457	[3]	997	[4]
Operating income		853	[1]	1,338	871	537	620	892	[2]	1,231	[3]	829	[4]	3,599		3,572		6,358
Net income		2,400	[1]	863	572	321	416	645	[2]	843	[3]	513	[4]	4,156		2,417		4,101
Net income attributable to Valero Energy Corporation stockholders		$ 2,371	[1]	$ 841	$ 548	$ 305	$ 367	$ 613	[2]	$ 814	[3]	$ 495	[4]	$ 4,065		$ 2,289		$ 3,990
Earnings per common share (in usd per share)		$ 5.43	[1]	$ 1.91	$ 1.23	$ 0.68	$ 0.81	$ 1.33	[2]	$ 1.74	[3]	$ 1.05	[4]	$ 9.17		$ 4.94		$ 8.00
Earnings per common share - assuming dilution (in usd per share)		$ 5.42	[1]	$ 1.91	$ 1.23	$ 0.68	$ 0.81	$ 1.33	[2]	$ 1.73	[3]	$ 1.05	[4]	$ 9.16		$ 4.94		$ 7.99
Quarterly Financial Data (Textual)
Income tax benefit related to Tax Reform		$ 1,900												$ 1,862		$ 7		$ 17
Lower of cost or market inventory valuation adjustment										$ (454)		$ (293)		0		(747)		790
Asset impairment loss										$ 56				0		56		0
Tax benefit on disposition								$ 42						$ 949		$ (765)		$ (1,870)

[1] During the quarter ended December 31, 2017, we recognized an income tax benefit of $1.9 billion related to Tax Reform as described in Note 14.

[2] During the quarter ended September 30, 2016, we recognized a tax benefit of $42 million related to the Aruba Disposition as described in Note 2.

[3] During the quarter ended June 30, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $454 million as described in Note 4 and an asset impairment loss of $56 million related to the Aruba Disposition as described in Note 2.

[4] During the quarter ended March 31, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $293 million as described in Note 4.

[5] Includes excise taxes on sales by certain of our international operations of $5,573 million, $5,493 million, and $5,980 million for the years ended December 31, 2017, 2016, and 2015.

[6] Gross profit is calculated as operating revenues less total cost of sales.