Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Oct. 31, 2019	Jan. 31, 2019
Property Plant And Equipment [Line Items]
Total property and equipment	$ 387,784	$ 329,526
Less: accumulated depreciation and amortization	(257,548)	(204,173)
Property and equipment, net	130,236	125,353
Test equipment
Property Plant And Equipment [Line Items]
Total property and equipment	199,878	170,930
Computer equipment and software
Property Plant And Equipment [Line Items]
Total property and equipment	139,188	117,330
Furniture and fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	8,483	6,980
Leasehold improvements
Property Plant And Equipment [Line Items]
Total property and equipment	$ 40,235	$ 34,286

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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