Loss Per Common Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Loss Per Common Unit
Net (loss) income	$ (143,124)	$ 52,492	$ (184,101)
Less: Net income attributable to noncontrolling interests	(631)	(1,106)	(655)
Net (loss) income attributable to NGL Energy Partners LP	(143,755)	51,386	(184,756)
Less: Distributions to preferred unitholders (1)	(139,644)	(124,691)	(104,163)
Less: Net loss allocated to GP (2)	283	73	289
Net loss allocated to common unitholders	$ (283,116)	$ (73,232)	$ (288,630)
Limited Partner
Loss Per Common Unit
Basic weighted average common units outstanding (in units)	132,146,477	131,007,171	129,840,234
DILUTED WEIGHTED AVERAGE COMMON UNITS OUTSTANDING (in units)	132,146,477	131,007,171	129,840,234
Net (loss) income	$ (143,472)	$ 51,459	$ (184,467)
Basic loss per common unit	$ (2.14)	$ (0.56)	$ (2.22)
Diluted loss per common unit	$ (2.14)	$ (0.56)	$ (2.22)