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