Cash Equivalents, Marketable Securities and Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jul. 31, 2014	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate carrying amount of portfolio of other investments		$ 12,600	$ 7,200
Investments in private medical device company		$ 6,400	$ 2,899	$ 750
ECP Entwicklungsgesellschaft mbH
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments to acquire businesses, cash paid	$ 13,000
Potential payouts payments	$ 15,000