Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 125,406	$ 77,178
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	14,807	9,724
Stock-based compensation	42,708	32,325
Deferred income taxes	(13,720)	(15,483)
Excess tax benefit on stock-based compensation	(30,043)	(32,381)
Amortization of investment premiums	994	1,332
Changes in operating assets and liabilities:
Accounts receivable	(65,980)	(63,248)
Inventories	(69,998)	(31,915)
Prepaid expenses and other current assets	(98,050)	(19,352)
Other assets	3,208	(3,092)
Accounts payable	35,510	(145)
Accrued liabilities	15,913	18,102
Deferred revenue	88,027	84,238
Income taxes payable	27,275	24,759
Other liabilities	2,628	1,980
Net cash provided by operating activities	78,685	84,022
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturity of marketable securities	41,917	58,200
Purchases of marketable securities	(342,484)	0
Purchases of property and equipment	(15,787)	(13,974)
Investment in privately-held companies	(2,500)	0
Change in restricted cash	0	(4,039)
Purchases of intangible assets	(697)	(743)
Net cash (used in) provided by investing activities	(319,551)	39,444
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments of lease financing obligations	(960)	(778)
Proceeds from issuance of common stock upon exercising options, net of repurchases	15,556	14,562
Minimum tax withholding paid on behalf of employees for net share settlement	(811)	0
Proceeds from issuance of common stock under employee stock purchase plan	10,326	9,366
Excess tax benefit on stock-based compensation	30,043	32,381
Issuance costs from initial public offering	0	(261)
Net cash provided by financing activities	54,154	55,270
Effect of exchange rate changes	(133)	(267)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(186,845)	178,469
CASH AND CASH EQUIVALENTS—Beginning of period	687,326	240,031
CASH AND CASH EQUIVALENTS—End of period	500,481	418,500
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for income taxes, net of refunds	34,426	3,806
Cash paid for interest—lease financing obligation	2,196	2,257
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:
Property and equipment included in accounts payable and accrued liabilities	$ 1,313	$ 916