BUSINESS SEGMENTS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2014
Segments of business
Total revenue	$ 40,638	$ 37,269	$ 122,400	$ 112,200
Direct operating costs and expenses	(17,048)	(16,655)	(50,657)	(47,481)
Net margins	23,590	20,614	71,743	64,719
Direct general and administrative expenses	(764)	(1,117)	(2,925)	(2,810)
Allocated general and administrative expenses	(2,841)	(2,835)	(8,524)	(8,440)
Allocated insurance expense	(969)	(944)	(2,776)	(2,812)
Reimbursement of bonus awards expense	(251)	(121)	(2,144)	(1,185)
Depreciation and amortization	(8,169)	(7,711)	(24,168)	(22,524)
Earnings (loss) from unconsolidated affiliates	2,960	2,191	6,940	9,764
Operating income	13,556	10,077	38,146	36,712
Other expenses	(1,671)	(2,365)	(7,241)	(6,690)
Net earnings	11,885	7,712	30,905	30,022	$ 41,689
External customers	39,328	27,143	115,570	79,196
Revenue from affiliates	1,310	10,126	6,830	33,004
Capital expenditures	10,139	8,784	34,105	24,538
Identifiable assets	430,162		430,162
Cash and cash equivalents	441	791	441	791	681	$ 28	$ 5,046	$ 3,304
Investments in unconsolidated affiliates	243,202		243,202		246,700
Deferred financing costs	1,501		1,501		1,721
Other	1,485		1,485
TOTAL ASSETS	676,791		676,791		656,687
Impairment of goodwill			0		$ 0
NGL Energy Partners LP
Segments of business
Revenue from affiliates		9,015	2,961	29,706
Frontera
Segments of business
Revenue from affiliates	1,310	1,111	3,869	3,298
Gulf Coast Terminals
Segments of business
Terminaling services fees, net	11,259	10,844	33,958	31,305
Other	3,539	2,202	7,869	6,459
Total revenue	14,798	13,046	41,827	37,764
Direct operating costs and expenses	(6,013)	(4,920)	(16,750)	(13,815)
Net margins	8,785	8,126	25,077	23,949
External customers	14,798	11,980	41,703	32,859
Capital expenditures	1,465	1,519	4,894	8,503
Identifiable assets	127,031		127,031
Gulf Coast Terminals | NGL Energy Partners LP
Segments of business
Revenue from affiliates		1,066	124	4,905
Midwest Terminals and Pipeline System
Segments of business
Terminaling services fees, net	2,207	2,206	6,427	6,299
Pipeline transportation fees	433	433	1,299	1,261
Other	200	585	697	1,098
Total revenue	2,840	3,224	8,423	8,658
Direct operating costs and expenses	(858)	(871)	(2,422)	(2,351)
Net margins	1,982	2,353	6,001	6,307
External customers	2,840	3,224	8,423	8,658
Capital expenditures	145	78	576	775
Identifiable assets	21,911		21,911
Brownsville terminals
Segments of business
Terminaling services fees, net	1,948	2,096	6,176	5,979
Pipeline transportation fees	1,223	1,183	3,691	3,687
Other	2,367	2,827	9,909	10,043
Total revenue	5,538	6,106	19,776	19,709
Direct operating costs and expenses	(2,573)	(3,269)	(8,742)	(9,479)
Net margins	2,965	2,837	11,034	10,230
External customers	4,228	4,995	15,907	16,401
Capital expenditures	126	1,188	759	3,455
Identifiable assets	43,630		43,630
Brownsville terminals | NGL Energy Partners LP
Segments of business
Revenue from affiliates				10
Brownsville terminals | Frontera
Segments of business
Revenue from affiliates	1,310	1,111	3,869	3,298
River terminals
Segments of business
Terminaling services fees, net	2,591	2,346	7,053	6,899
Other	221	114	2,559	547
Total revenue	2,812	2,460	9,612	7,446
Direct operating costs and expenses	(1,753)	(1,898)	(6,034)	(5,255)
Net margins	1,059	562	3,578	2,191
External customers	2,812	2,343	9,612	7,095
Capital expenditures	209	832	1,565	3,875
Identifiable assets	52,589		52,589
River terminals | NGL Energy Partners LP
Segments of business
Revenue from affiliates		117		351
Southeast Terminals
Segments of business
Terminaling services fees, net	13,287	11,521	39,864	34,789
Other	1,363	912	2,898	3,834
Total revenue	14,650	12,433	42,762	38,623
Direct operating costs and expenses	(5,851)	(5,697)	(16,709)	(16,581)
Net margins	8,799	6,736	26,053	22,042
External customers	14,650	4,601	39,925	14,183
Capital expenditures	8,194	5,167	26,311	7,930
Identifiable assets	$ 185,001		185,001
Southeast Terminals | NGL Energy Partners LP
Segments of business
Revenue from affiliates		$ 7,832	$ 2,837	$ 24,440