Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Mar. 31, 2018 USD ($) Customer shares	Mar. 31, 2017 USD ($) Customer shares	Mar. 31, 2016 USD ($) Customer shares	Apr. 01, 2017 USD ($)
Summary Of Significant Accounting Policy [Line Items]
Product warranty period	1 year
Reclassifications out of accumulated other comprehensive income (loss)	$ 0	$ 0	$ 0
Expected dividend yield	0.00%
Excess tax benefits related to restricted stock unit vestings or stock option exercises, decrease in financing activities		12,038,000	3,567,000
Excess tax benefits related to restricted stock unit vestings or stock option exercises, increase in operating activities		$ 12,038,000	$ 3,567,000
ASU 2016-09
Summary Of Significant Accounting Policy [Line Items]
Excess tax benefit	$ 31,000,000
Excess tax benefits related to restricted stock unit vestings or stock option exercises, decrease in financing activities	31,000,000
Excess tax benefits related to restricted stock unit vestings or stock option exercises, increase in operating activities	$ 31,000,000
Increase additional paid in capital				$ 1,800,000
Increase deferred tax assets				700,000
Decrease retained earnings				(1,100,000)
Adjustment to Increase Retained Earnings and Deferred Tax Assets | ASU 2016-09
Summary Of Significant Accounting Policy [Line Items]
Cumulative effect to increase retained earnings and deferred tax assets				$ 76,400,000
Stock Options and Performance Shares
Summary Of Significant Accounting Policy [Line Items]
Shares excluded from the calculation of diluted weighted average shares outstanding | shares	155,000	24,000	62,000
Leasehold Improvements
Summary Of Significant Accounting Policy [Line Items]
Leasehold improvements, useful life	shorter of the lease term or the estimated useful lives
Minimum | Machinery and Equipment
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	3 years
Minimum | Computer Software
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	3 years
Minimum | Furniture and Fixtures
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	3 years
Minimum | Building and Building Improvements
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	7 years
Maximum | Machinery and Equipment
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	5 years
Maximum | Computer Software
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	5 years
Maximum | Furniture and Fixtures
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	5 years
Maximum | Building and Building Improvements
Summary Of Significant Accounting Policy [Line Items]
Property and Equipment, useful life	33 years
Customer Concentration Risk | Total Revenues
Summary Of Significant Accounting Policy [Line Items]
Number of customer accounted more than 10% of total revenue / total receivable | Customer	0	0	0
Customer Concentration Risk | Total Revenues | Minimum
Summary Of Significant Accounting Policy [Line Items]
Percentage of concentration risk	10.00%	10.00%	10.00%
Customer Concentration Risk | Total Accounts Receivable
Summary Of Significant Accounting Policy [Line Items]
Number of customer accounted more than 10% of total revenue / total receivable | Customer	0	0
Customer Concentration Risk | Total Accounts Receivable | Minimum
Summary Of Significant Accounting Policy [Line Items]
Percentage of concentration risk	10.00%	10.00%