Partners' Capital - Additional Information (Details) - USD ($)				1 Months Ended		3 Months Ended					12 Months Ended
	Jul. 16, 2015	Jul. 01, 2015	Jun. 19, 2015	Feb. 29, 2016	Jan. 31, 2015	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Proceeds of equity offering and overallotment exercise, net of issuance costs, Units											35,993	107,227	90,671
Issuance of units to CST in connection with sale of fuel supply interests and purchase of NTIs, Units		3,303,208			1,497,946
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest		12.50%			5.00%
Partners' Capital Account, Units, Sold in Public Offering	200,000		4,600,000
Proceeds from issuance of common units	$ 6,400,000		$ 138,500,000
Stock Repurchase Program, Authorized Amount						$ 25,000,000					$ 25,000,000
Amount Remaining under the Program						$ 18,144,276				$ 18,144,276	18,144,276	$ 18,144,276	$ 21,396,929
Total Cost of Units Purchased											$ 6,855,724	$ 3,252,653	$ 3,603,071
Total Number of Units Purchased											287,621	133,463	154,158
Average Price Paid per Unit											$ 23.84	$ 24.37	$ 23.37
Cash Distribution (per unit)				$ 0.5925		$ 0.6275	$ 0.6275	$ 0.6225	$ 0.6175	$ 0.6125
CST Brands Inc. [Member]
Amount Remaining under the Program						$ 50,000,000					$ 50,000,000
Total Cost of Units Purchased											$ 0	$ 0	$ 19,800,000
Total Number of Units Purchased													804,667
Average Price Paid per Unit													$ 25
Common Unit Repurchase Program [Member]
Share purchases under Program											0
Erickson [Member]
Issuance of units to CST in connection with sale of fuel supply interests and purchase of NTIs, Units		338,098