Commitments and Contingencies (Details)	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($) bbl
Commitments and Contingencies
Operating expense recorded in statement of operations	$ 64,137,000	$ 69,377,000	$ 65,584,000
Operating leases
Rental expenses	6,070,785	5,741,000	4,806,000
Operating Leases, Future Minimum Payments Due
2017	4,670,000
2018	3,850,000
2019	2,471,000
2020	772,000
2021	328,000
Thereafter	4,556,000
Total operating lease future payments	16,647,000
Refined products terminals and storage | North Little Rock, Arkansas
Commitments and Contingencies
Total Value of Products For Specified Contingency			$ 2,259,000
Estimated volume of products to be returned to customers | bbl			24,000
Volume of products returned to customers | bbl			20,900
Value of products returned to customers		$ 172,000	$ 2,092,000
Remaining volume of products to be returned to customers | bbl			3,100
Remaining value of products to be returned to customers			$ 167,000
Parnon Storage, LLC
Operating leases
Land lease monthly payment	$ 10,000
Land lease remaining lease period	41 years