Restructuring, Impairment and Other Costs - Narrative (Details)			1 Months Ended	3 Months Ended		12 Months Ended
	Mar. 26, 2018 USD ($) shares	May 19, 2016 USD ($)	Jan. 31, 2017 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring, impairment and other costs (reversal)				$ 600,000		$ (639,000)	$ 0	$ 5,264,000
Number of positions eliminated							47
Asset impairment						0	$ 0	3,909,000
Out of period adjustment of accounts payable					$ 600,000
Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring, impairment and other costs (reversal)							$ 0	768,000
Costs Relating to Streamlining Operations and Asset Write-Offs
Restructuring Cost and Reserve [Line Items]
Restructuring, impairment and other costs (reversal)					$ 3,500,000
Craig Separation Agreement | Salaries, Wages and Employee Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring, impairment and other costs (reversal)						700,000
Craig Separation Agreement | Employee Severance
Restructuring Cost and Reserve [Line Items]
Severance pay, annual salary	$ 350,000
Severance pay period	1 year
Craig Separation Agreement | Employee Severance | Salaries, Wages and Employee Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring, impairment and other costs (reversal)						$ 200,000
Rogers Separation Agreement | Employee Severance
Restructuring Cost and Reserve [Line Items]
Term for base salary continuation			1 year
Rogers Separation Agreement | Employee Severance | Salaries, Wages and Employee Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring, impairment and other costs (reversal)			$ 600,000
Rhodes Separation Agreement | Employee Severance
Restructuring Cost and Reserve [Line Items]
Distribution paid			171,125
Rhodes Separation Agreement | Employee Severance | Salaries, Wages and Employee Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring, impairment and other costs (reversal)			200,000
Separation Agreement | Employee Severance | Salaries, Wages and Employee Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring, impairment and other costs (reversal)		$ 700,000
Base Salary Continuation | Rogers Separation Agreement | Employee Severance
Restructuring Cost and Reserve [Line Items]
Distribution paid			425,000
Separation Payment | Rogers Separation Agreement | Employee Severance
Restructuring Cost and Reserve [Line Items]
Distribution paid			120,000
Moving and Transition Expenses | Rogers Separation Agreement | Employee Severance
Restructuring Cost and Reserve [Line Items]
Distribution paid			$ 30,000
Contractor
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated							2
Non-operating Assets
Restructuring Cost and Reserve [Line Items]
Asset impairment								1,100,000
Bulk Fuel Assets
Restructuring Cost and Reserve [Line Items]
Asset impairment								500,000
Spartanburg Terminal
Restructuring Cost and Reserve [Line Items]
Asset impairment								$ 600,000
Time-Vested Restricted Stock
Restructuring Cost and Reserve [Line Items]
Number of accelerated vesting shares (in shares) | shares	5,488
Performance-Vested Restricted Stock
Restructuring Cost and Reserve [Line Items]
Number of accelerated vesting shares (in shares) | shares	5,488