Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Non-Leased Assets
Property and equipment excluding assets subject to operating lease, at cost	$ 384,834	$ 375,157
Accumulated depreciation, property and equipment excluding assets subject to operating lease	(118,091)	(115,538)
Property and equipment excluding assets subject to operating lease, net	266,743	259,619
Assets Leased to Valero
Assets under operating leases, at cost	917,773	841,131
Accumulated depreciation, assets under operating leases	(244,350)	(235,670)
Assets under operating leases, net	673,423	605,461
Property and Equipment, Total
Property and equipment, at cost	1,302,607	1,216,288
Accumulated depreciation	(362,441)	(351,208)
Property and equipment, net	940,166	865,080
Land [Member]
Non-Leased Assets
Property and equipment excluding assets subject to operating lease, at cost	4,672	4,672
Assets Leased to Valero
Assets under operating leases, at cost	0	0
Property and Equipment, Total
Property and equipment, at cost	4,672	4,672
Pipelines and Related Assets [Member]
Non-Leased Assets
Property and equipment excluding assets subject to operating lease, at cost	224,794	224,656
Assets Leased to Valero
Assets under operating leases, at cost	112,738	47,366
Property and Equipment, Total
Property and equipment, at cost	337,532	272,022
Terminals and Related Assets [Member]
Non-Leased Assets
Property and equipment excluding assets subject to operating lease, at cost	114,127	112,614
Assets Leased to Valero
Assets under operating leases, at cost	805,035	793,765
Property and Equipment, Total
Property and equipment, at cost	919,162	906,379
Other [Member]
Non-Leased Assets
Property and equipment excluding assets subject to operating lease, at cost	10,016	9,538
Assets Leased to Valero
Assets under operating leases, at cost	0	0
Property and Equipment, Total
Property and equipment, at cost	10,016	9,538
Construction-in-Progress [Member]
Non-Leased Assets
Property and equipment excluding assets subject to operating lease, at cost	31,225	23,677
Assets Leased to Valero
Assets under operating leases, at cost	0	0
Property and Equipment, Total
Property and equipment, at cost	$ 31,225	$ 23,677