SEGMENT REPORTING - Reconciliation of Adjusted EBITDA to Loss from Continuing Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Adjusted EBITDA
Services Adjusted EBITDA	$ 13,422	$ 16,180	$ 43,884	$ 46,859
Add (deduct):
Amortization of deferred financing costs	216	216	646	646
Deferred income taxes	(221)	98	86	2
Changes in accounts receivable and other assets	3,215	(4,309)	1,862	(2,802)
Changes in accounts payable and accrued expenses	2,033	2,027	947	90
Changes in deferred revenue and other liabilities	(3,147)	(2,599)	(5,667)	(499)
Change in restricted cash	915	(31)	685	(664)
Interest expense, net	(2,384)	(2,572)	(7,500)	(7,288)
Provision for (benefit from) income taxes	178	5,579	1,427	1,865
Foreign currency transaction gain (loss)	457	(25)	527	120
Deferred revenue associated with minimum monthly commitment fees	1,473	(43)	1,331	(1,230)
Net cash provided by operating activities	16,157	14,521	38,228	37,099
Operating Segments | Terminalling services
Segment Adjusted EBITDA
Services Adjusted EBITDA	14,186	17,080	46,434	50,310
Add (deduct):
Provision for (benefit from) income taxes	343	5,739	1,761	2,008
Foreign currency transaction gain (loss)	20	(31)	33	44
Operating Segments | Fleet services
Segment Adjusted EBITDA
Services Adjusted EBITDA	383	428	1,202	1,387
Add (deduct):
Provision for (benefit from) income taxes	(196)	(160)	(511)	(142)
Foreign currency transaction gain (loss)	(4)	2	(6)	72
Corporate
Segment Adjusted EBITDA
Services Adjusted EBITDA	(1,147)	(1,328)	(3,752)	(4,838)
Add (deduct):
Provision for (benefit from) income taxes	31	0	177	(1)
Foreign currency transaction gain (loss)	$ 441	$ 4	$ 500	$ 4