Unaudited Condensed Consolidating Guarantor and Non-Guarantor Financial Information - Unaudited Condensed Consolidating Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Unaudited Condensed Consolidating Statement of Operations
REVENUES	$ 4,289,336	$ 5,115,975	$ 9,455,761	$ 9,375,047
COST OF SALES	4,057,376	4,945,204	9,052,342	9,151,432
OPERATING COSTS AND EXPENSES:
Operating	75,433	58,510	137,529	112,977
General and administrative	43,908	39,328	64,250	61,669
Depreciation and amortization	63,113	52,598	116,867	104,490
Loss on disposal or impairment of assets, net	3,111	5,988	2,144	107,323
Revaluation of liabilities	0	0	0	800
Operating Income (Loss)	46,395	14,347	82,629	(163,644)
OTHER INCOME (EXPENSE):
Equity in earnings of unconsolidated entities	(265)	379	(257)	598
Interest expense	(45,016)	(41,358)	(84,910)	(87,625)
(Loss) gain on early extinguishment of liabilities, net	0	0	0	(137)
Other income (expense), net	184	1,301	1,193	(32,602)
Income (Loss) From Continuing Operations Before Income Taxes	1,298	(25,331)	(1,345)	(283,410)
INCOME TAX EXPENSE	(640)	(691)	(319)	(1,342)
Income (Loss) From Continuing Operations	658	(26,022)	(1,664)	(284,752)
(Loss) Income From Discontinued Operations, net of Tax	(202,024)	380,961	(191,663)	470,402
Net (Loss) Income	(201,366)	354,939	(193,327)	185,650
LESS: NET LOSS ATTRIBUTABLE TO NONCONTROLLING INTERESTS	129	518	397	863
LESS: NET LOSS ATTRIBUTABLE TO REDEEMABLE NONCONTROLLING INTERESTS	0	48	0	446
NET (LOSS) INCOME ATTRIBUTABLE TO NGL ENERGY PARTNERS LP	(201,237)	355,505	(192,930)	186,959
Reportable Entity | NGL Energy Partners LP (Parent)
OTHER INCOME (EXPENSE):
Interest expense	(26,666)	(29,485)	(52,455)	(58,985)
(Loss) gain on early extinguishment of liabilities, net				(137)
Income (Loss) From Continuing Operations Before Income Taxes	(26,666)	(29,485)	(52,455)	(59,122)
EQUITY IN NET INCOME (LOSS) OF CONSOLIDATED SUBSIDIARIES	(174,571)	384,990	(140,475)	246,081
Income (Loss) From Continuing Operations	(201,237)	355,505	(192,930)	186,959
(Loss) Income From Discontinued Operations, net of Tax	0	0	0	0
Net (Loss) Income	(201,237)	355,505	(192,930)	186,959
NET (LOSS) INCOME ATTRIBUTABLE TO NGL ENERGY PARTNERS LP	(201,237)	355,505	(192,930)	186,959
Reportable Entity | Guarantor Subsidiaries
Unaudited Condensed Consolidating Statement of Operations
REVENUES	4,272,431	5,115,057	9,425,327	9,370,234
COST OF SALES	4,058,083	4,946,062	9,054,283	9,153,124
OPERATING COSTS AND EXPENSES:
Operating	69,052	56,470	126,813	108,847
General and administrative	43,646	39,139	63,778	61,138
Depreciation and amortization	59,370	50,391	110,234	99,369
Loss on disposal or impairment of assets, net	3,115	5,988	2,148	107,323
Revaluation of liabilities		800		800
Operating Income (Loss)	39,165	16,207	68,071	(160,367)
OTHER INCOME (EXPENSE):
Equity in earnings of unconsolidated entities	(265)	379	(257)	598
Interest expense	(18,350)	(11,874)	(32,455)	(28,640)
(Loss) gain on early extinguishment of liabilities, net				0
Other income (expense), net	164	1,313	1,176	(32,394)
Income (Loss) From Continuing Operations Before Income Taxes	20,714	6,025	36,535	(220,803)
INCOME TAX EXPENSE	(640)	(691)	(319)	(1,342)
EQUITY IN NET INCOME (LOSS) OF CONSOLIDATED SUBSIDIARIES	7,379	(1,373)	14,972	(3,020)
Income (Loss) From Continuing Operations	27,453	3,961	51,188	(225,165)
(Loss) Income From Discontinued Operations, net of Tax	(202,024)	381,029	(191,663)	471,246
Net (Loss) Income	(174,571)	384,990	(140,475)	246,081
NET (LOSS) INCOME ATTRIBUTABLE TO NGL ENERGY PARTNERS LP	(174,571)	384,990	(140,475)	246,081
Reportable Entity | Non-Guarantor Subsidiaries
Unaudited Condensed Consolidating Statement of Operations
REVENUES	18,369	1,789	33,374	6,482
COST OF SALES	507	13	499	(23)
OPERATING COSTS AND EXPENSES:
Operating	6,631	2,040	11,216	4,130
General and administrative	262	189	472	531
Depreciation and amortization	3,743	2,207	6,633	5,121
Loss on disposal or impairment of assets, net	(4)	0	(4)	0
Revaluation of liabilities		(800)		0
Operating Income (Loss)	7,230	(1,860)	14,558	(3,277)
OTHER INCOME (EXPENSE):
Interest expense	(12)	(11)	(23)	(23)
Other income (expense), net	32	0	40	0
Income (Loss) From Continuing Operations Before Income Taxes	7,250	(1,871)	14,575	(3,300)
INCOME TAX EXPENSE	0	0	0	0
Income (Loss) From Continuing Operations	7,250	(1,871)	14,575	(3,300)
(Loss) Income From Discontinued Operations, net of Tax	0	(68)	0	(1,029)
Net (Loss) Income	7,250	(1,939)	14,575	(4,329)
NET (LOSS) INCOME ATTRIBUTABLE TO NGL ENERGY PARTNERS LP	7,250	(1,939)	14,575	(4,329)
Consolidating Adjustments
Unaudited Condensed Consolidating Statement of Operations
REVENUES	(1,464)	(871)	(2,940)	(1,669)
COST OF SALES	(1,214)	(871)	(2,440)	(1,669)
OPERATING COSTS AND EXPENSES:
Operating	(250)		(500)
OTHER INCOME (EXPENSE):
Interest expense	12	12	23	23
Other income (expense), net	(12)	(12)	(23)	(208)
Income (Loss) From Continuing Operations Before Income Taxes	0	0	0	(185)
EQUITY IN NET INCOME (LOSS) OF CONSOLIDATED SUBSIDIARIES	167,192	(383,617)	125,503	(243,061)
Income (Loss) From Continuing Operations	167,192	(383,617)	125,503	(243,246)
(Loss) Income From Discontinued Operations, net of Tax	0	0	0	185
Net (Loss) Income	167,192	(383,617)	125,503	(243,061)
LESS: NET LOSS ATTRIBUTABLE TO NONCONTROLLING INTERESTS	129	518	397	863
LESS: NET LOSS ATTRIBUTABLE TO REDEEMABLE NONCONTROLLING INTERESTS		48		446
NET (LOSS) INCOME ATTRIBUTABLE TO NGL ENERGY PARTNERS LP	$ 167,321	$ (383,051)	$ 125,900	$ (241,752)