Tax Receivable Agreements (Aggregate Payments Due Under Tax Receivable Agreements (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Mar. 31, 2020
Related Party Transaction [Line Items]
Tax receivable agreement long-term obligations due to related parties	$ 98,658	$ 177,826
Related Party Tax Receivable Agreements [Member]
Related Party Transaction [Line Items]
Remainder of 2021
2022	11,606
2023	47,521
2024	30,544
2025	15,381
Thereafter	73,666
Gross expected payments	178,718
Less: Amounts representing discount	(68,454)
Total tax receivable agreement obligations due to related parties	110,264
Less: Current portion due (included in accrued expenses)	(11,606)
Tax receivable agreement long-term obligations due to related parties	98,658
Other Tax Receivable Agreements [Member]
Related Party Transaction [Line Items]
Remainder of 2021
2022	10,788
2023	19,947
2024	15,366
2025	10,977
Thereafter	58,755
Gross expected payments	115,833
Less: Amounts representing discount	(37,541)
Total tax receivable agreement obligations due to related parties	78,292
Less: Current portion due (included in accrued expenses)	(10,788)
Tax receivable agreement long-term obligations due to related parties	67,504
McKesson Tax Receivable Agreement [Member]
Related Party Transaction [Line Items]
Remainder of 2021
2022	128
2023	18,306
2024	19,905
2025	23,150
Thereafter	103,144
Gross expected payments	164,633
Total tax receivable agreement obligations due to related parties	164,633
Less: Current portion due (included in accrued expenses)	(128)
Tax receivable agreement long-term obligations due to related parties	$ 164,505