Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Dec. 31, 2019	Mar. 31, 2019
Accounts receivable - trade, allowance for doubtful accounts	$ 4,055	$ 4,016
PROPERTY, PLANT AND EQUIPMENT, accumulated depreciation	504,731	417,457
INTANGIBLE ASSETS, accumulated amortization	603,573	503,117
Debt issuance costs, noncurrent, net	$ 20,263	$ 12,008
General partner interest	0.10%	0.10%
General partner, notional units outstanding (in units)	128,477	124,633
Limited partner interest	99.90%	99.90%
Limited partners, common units issued (in units)	128,348,906	124,508,497
Limited partners, common units outstanding (in units)	128,348,906	124,508,497
Class A Convertible Preferred Units
Preferred units dividend rate		10.75%
Temporary equity, issued (in units)		19,942,169
Temporary equity, outstanding (in units)		19,942,169
Class D Preferred Units
Preferred units dividend rate	9.00%
Temporary equity, issued (in units)	600,000
Temporary equity, outstanding (in units)	600,000
Class B Perpetual Preferred Units
Preferred units, issued (in units)	12,585,642	8,400,000
Preferred units, outstanding (in units)	12,585,642	8,400,000
Class C Perpetual Preferred Units
Preferred units, issued (in units)	1,800,000
Preferred units, outstanding (in units)	1,800,000

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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