Balance Sheet Components - Components of Certain Balance Sheet Asset Amounts (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Mar. 31, 2017
Accounts receivable, net:
Accounts receivable	$ 668,811	$ 395,754
Accounts receivable, net	351,753	185,179
Inventories:
Raw materials	35,752	30,582
Finished goods	243,227	222,819
Inventory, net	278,979	253,401
Other current assets:
Value-added tax receivables	29,620	23,132
Prepaid expenses and other assets	27,910	18,600
Other current assets, total	57,530	41,732
Property, plant and equipment, net:
Property, plant and equipment at cost	362,809	348,760
Less: accumulated depreciation and amortization	(275,908)	(263,352)
Property, plant and equipment, net	86,901	85,408
Other assets:
Deferred tax assets	86,518	57,303
Trading investments for deferred compensation plan	17,998	15,043
Investments in privately held companies	11,969	10,776
Other assets	6,354	4,997
Other assets, total	122,839	88,119
Allowance for doubtful accounts
Accounts receivable, net:
Valuation allowance for accounts receivable	(233)	(607)
Allowance for sales returns
Accounts receivable, net:
Valuation allowance for accounts receivable	(25,008)	(18,800)
Allowance for cooperative marketing arrangements
Accounts receivable, net:
Valuation allowance for accounts receivable	(44,033)	(28,022)
Allowance for customer incentive programs
Accounts receivable, net:
Valuation allowance for accounts receivable	(102,974)	(60,857)
Allowance for pricing programs
Accounts receivable, net:
Valuation allowance for accounts receivable	$ (144,810)	$ (102,289)