Income Taxes (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Abstract]
Income tax expense (benefit)	$ 15,240,000	$ (5,080,000)	$ (564,000)	$ (16,664,000)
Effective income tax rate	23.10%	29.10%	0.70%	25.60%
Tax receivable agreement, percentage of net cash saving realized assigned			85.00%
Tax receivable agreement, minimum percentage of the Joint Venture outstanding units required to be owned			20.00%
Additional tax receivable agreement, percentage net cash tax savings Company required to pay arising from certain tax basis increases and imputed interest deductions			85.00%
Net cash tax savings, obligation	$ 0		$ 0
Letter agreement, percentage of tax savings required to pay if amount of deductions allocated to Company are in excess of specified minimum threshold			100.00%
Due to McKesson	$ 47,172,000		$ 47,172,000