Cash Distributions (Details) - USD ($) $ / shares in Units, $ in Thousands								3 Months Ended		6 Months Ended
	Jul. 23, 2018	May 09, 2018	Feb. 13, 2018	Nov. 09, 2017	Aug. 10, 2017	May 11, 2017	Feb. 10, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Quarterly Cash Distributions
Total quarterly distribution (dollars per unit)		$ 0.5275	$ 0.5075	$ 0.48	$ 0.4550	$ 0.4275	$ 0.4065	$ 0.551	$ 0.455	$ 1.0785	$ 0.8825
Distributions		$ 52,826	$ 50,055	$ 46,242	$ 42,111	$ 38,043	$ 34,895	$ 56,081	$ 42,111	$ 108,907	$ 80,154
General Partner’s Distributions [Member]
Quarterly Cash Distributions
Distributions								17,918	11,092	34,208	19,994
General Partner Valero [Member]
Quarterly Cash Distributions
Distributions								1,122	842	2,178	1,437
General Partner IDRs [Member]
Quarterly Cash Distributions
Distributions								16,796	10,250	32,030	18,557
Limited Partner [Member]
Quarterly Cash Distributions
Distributions								38,156	31,014	74,686	60,150
Limited Partner [Member] | Common Unitholders Public [Member]
Quarterly Cash Distributions
Distributions								12,387	10,226	24,246	19,831
Limited Partner [Member] | Common Unitholder Valero [Member]
Quarterly Cash Distributions
Distributions								25,769	20,788	50,440	40,319
Distribution Equivalent Rights [Member]
Quarterly Cash Distributions
Distributions								$ 7	$ 5	$ 13	$ 10
Subsequent Event [Member]
Quarterly Cash Distributions
Total quarterly distribution (dollars per unit)	$ 0.5510
Distributions	$ 56,081