Summary of Significant Accounting Policies - Schedule of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Costs and expenses:
Total share-based compensation	$ 19,694	$ 16,102	$ 12,196
Estimated income tax benefit	(4,726)	(3,859)	(4,125)
Decrease in net income	14,968	12,243	8,071
Cost of Revenue
Costs and expenses:
Total share-based compensation	2,051	1,252	938
Research and Development Costs
Costs and expenses:
Total share-based compensation	3,875	2,919	2,038
Selling, General and Administrative
Costs and expenses:
Total share-based compensation	$ 13,768	$ 11,931	$ 9,220