Goodwill (Details) $ in Thousands	6 Months Ended
Sep. 30, 2019 USD ($)
Goodwill [Roll Forward]
Goodwill at the beginning of the period	$ 1,113,149
Revisions to acquisition accounting (Note 4)	2,698
Acquisitions (Note 4)	60,195
Goodwill at the end of the period	1,176,042
Crude oil logistics
Goodwill [Roll Forward]
Goodwill at the beginning of the period	579,846
Revisions to acquisition accounting (Note 4)	0
Acquisitions (Note 4)	0
Goodwill at the end of the period	579,846
Water solutions
Goodwill [Roll Forward]
Goodwill at the beginning of the period	410,139
Revisions to acquisition accounting (Note 4)	4,755
Acquisitions (Note 4)	60,195
Goodwill at the end of the period	475,089
Liquids
Goodwill [Roll Forward]
Goodwill at the beginning of the period	103,421
Revisions to acquisition accounting (Note 4)	(2,057)
Acquisitions (Note 4)	0
Goodwill at the end of the period	101,364
Refined products and renewables
Goodwill [Roll Forward]
Goodwill at the beginning of the period	19,743
Revisions to acquisition accounting (Note 4)	0
Acquisitions (Note 4)	0
Goodwill at the end of the period	$ 19,743

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

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-Publisher FASB
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Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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