Segment Reporting - Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues
Railroad incentives									$ 434	$ 719	$ 0
Fleet leases									7,710		13,572
Freight and other reimbursables									1,880	2,141	1,778
Operating revenue	$ 26,063	$ 21,797	$ 20,395	$ 13,508	$ 12,191	$ 12,986	$ 5,436	$ 5,485	81,763	36,098	26,301
Operating costs
Subcontracted rail services									7,710	6,994	1,898
Pipeline fees									17,249	3,625	0
Fleet leases									11,833	8,788	13,572
Freight and other reimbursables									1,965	2,605	4,402
Selling, general and administrative									14,442	10,808	4,458
Depreciation and amortization									6,110	2,631	502
Total operating costs	17,232	14,746	14,588	12,743	11,795	10,963	7,216	5,477	59,309	35,451	24,832
Operating income	8,831	7,051	5,807	765	396	2,023	(1,780)	8	22,454	647	1,469
Interest expense									4,368	4,825	3,241
Gain associated with derivative instruments									(5,161)	(1,536)	0
Foreign currency transaction loss (gain)									201	(4,850)	(39)
Provision for income taxes									5,755	186	30
Income (loss) from continuing operations	6,675	$ 6,325	$ 2,652	$ 2,041	(1,229)	$ (1,179)	$ (4,199)	$ (1,071)	17,693	(7,678)	(1,841)
Total assets	328,398				148,280				328,398	148,280	77,192
Capital expenditures									1,671	33,736	56,114
Continuing Operations
Operating costs
Total assets	328,398				148,280				328,398	148,280	77,192
Related party
Revenues
Revenues										1,501
Fleet leases									4,123
Freight and other reimbursables									85	464	2,624
Terminalling services
Revenues
Revenues									58,841	18,266	7,130
Terminalling services | Related party
Revenues
Revenues									5,228	3,499	0
Fleet services
Revenues
Revenues									622	720	235
Fleet leases									7,710	8,788	13,572
Fleet services | Related party
Revenues
Revenues									2,840	1,501	962
Fleet leases									4,123	0	0
Operating Segments
Revenues
Railroad incentives										719
Operating Segments | Terminalling services
Revenues
Revenues									58,841	18,266	7,130
Railroad incentives									434
Operating revenue									64,503	22,484	7,130
Operating costs
Subcontracted rail services									7,710	6,994	1,898
Pipeline fees									17,249	3,625
Selling, general and administrative									5,924	6,290	3,704
Depreciation and amortization									6,110	2,631	502
Total operating costs									36,993	19,540	6,104
Operating income									27,510	2,944	1,026
Interest expense									2,026	3,600	3,241
Gain associated with derivative instruments									(5,161)	(1,536)
Foreign currency transaction loss (gain)									(166)	(4,406)	(39)
Provision for income taxes									5,581	47	21
Income (loss) from continuing operations									24,898	(3,573)	(2,275)
Total assets	316,232				105,093				316,232	105,093	68,995
Capital expenditures									1,671	33,736	56,114
Operating Segments | Terminalling services | Related party
Revenues
Revenues									5,228	3,499
Operating Segments | Fleet services
Revenues
Revenues									622	720	235
Fleet leases									7,710	8,788	13,572
Freight and other reimbursables									1,880	2,141	1,778
Operating revenue									17,260	13,614	19,171
Operating costs
Fleet leases									11,833	8,788	13,572
Freight and other reimbursables									1,965	2,605	4,402
Selling, general and administrative									1,035	2,650	380
Depreciation and amortization									0	0	0
Total operating costs									14,833	14,043	18,354
Operating income									2,427	(429)	817
Interest expense									0	0	0
Foreign currency transaction loss (gain)									(43)	17	0
Provision for income taxes									173	140	9
Income (loss) from continuing operations									2,211	(552)	808
Total assets	5,719				7,692				5,719	7,692	8,197
Capital expenditures									0	0	0
Operating Segments | Fleet services | Related party
Revenues
Revenues									2,840	1,501	962
Fleet leases									4,123
Freight and other reimbursables									85	464	2,624
Corporate
Operating costs
Selling, general and administrative									7,483	1,868	374
Depreciation and amortization									0	0	0
Total operating costs									7,483	1,868	374
Operating income									(7,483)	(1,868)	(374)
Interest expense									2,342	1,225	0
Foreign currency transaction loss (gain)									410	(461)	0
Provision for income taxes									1	(1)	0
Income (loss) from continuing operations									(9,416)	(3,553)	(374)
Total assets	$ 6,447				$ 35,495				6,447	35,495	0
Capital expenditures									$ 0	$ 0	$ 0