Net Income Per Limited Partner Unit (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Allocation of net income to determine net income available to limited partners:
Distributions, excluding general partner’s IDRs	$ 39,278	$ 31,856	$ 76,864	$ 61,587
General partner’s IDRs	16,796	10,250	32,030	18,557
DERs	7	5	13	10
Distributions and DERs declared	56,081	42,111	108,907	80,154
Undistributed earnings	7,938	16,332	21,191	36,426
Net income available to limited partners – basic and diluted	$ 64,019	$ 58,443	$ 130,098	$ 116,580
Net income per limited partner common unit – basic and diluted:
Weighted-average units outstanding (units)	69,251	68,157	69,250	67,912
Net income per limited partner common unit – basic and diluted (dollars per unit)	$ 0.66	$ 0.69	$ 1.38	$ 1.41
General Partner Valero [Member]
Allocation of net income to determine net income available to limited partners:
Distributions, excluding general partner’s IDRs	$ 1,122	$ 842	$ 2,178	$ 1,437
General partner’s IDRs	16,796	10,250	32,030	18,557
Distributions and DERs declared	17,918	11,092	34,208	19,994
Undistributed earnings	159	327	424	892
Net income available to limited partners – basic and diluted	18,077	11,419	34,632	20,886
Limited Partner [Member] | Limited Partners Common Units [Member]
Allocation of net income to determine net income available to limited partners:
Distributions, excluding general partner’s IDRs	38,156	31,014	74,686	60,150
Distributions and DERs declared	38,156	31,014	74,686	60,150
Undistributed earnings	7,778	16,002	20,764	35,527
Net income available to limited partners – basic and diluted	$ 45,934	$ 47,016	$ 95,450	$ 95,677
Net income per limited partner common unit – basic and diluted:
Weighted-average units outstanding (units)	69,251	68,157	69,250	67,912
Net income per limited partner common unit – basic and diluted (dollars per unit)	$ 0.66	$ 0.69	$ 1.38	$ 1.41
Restricted Units [Member]
Allocation of net income to determine net income available to limited partners:
DERs	$ 7	$ 5	$ 13	$ 10
Distributions and DERs declared	7	5	13	10
Undistributed earnings	1	3	3	7
Net income available to limited partners – basic and diluted	$ 8	$ 8	$ 16	$ 17