Common Stock and Stockholders' Equity - Schedule of Stock-based Compensation Expense Attributed to Cost of Revenue, Research and Development, Sales and Marketing and General and Administrative Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 21,188	$ 11,027
Cost of revenue
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	1,222	693
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	7,028	3,263
Sales and marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	9,059	4,790
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation expense	$ 3,879	$ 2,281