Share-Based Compensation (Share-Based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	$ 11,863	$ 6,924	$ 23,125	$ 14,736
R&D expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	5,060	3,725	9,167	7,749
SG&A expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	$ 6,803	$ 3,199	$ 13,958	$ 6,987