Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 184,189	$ 121,102	$ 86,850
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	19,749	13,671	10,021
Stock-based compensation	59,032	45,303	27,619
Deferred income taxes	(21,720)	(24,409)	(6,774)
Excess tax benefit on stock based-compensation	(42,855)	(37,251)	(17,436)
Amortization of investment premiums	1,493	1,471	348
Realized gain on notes receivable	0	0	(4,000)
Amortization of debt discount	0	0	527
Write-off of debt discount on notes payable	0	0	680
Changes in operating assets and liabilities:
Accounts receivable, net	(108,856)	(47,281)	(18,984)
Inventories	(144,361)	(14,123)	(13,425)
Prepaid expenses and other current assets	(115,074)	(7,827)	(15,257)
Other assets	2,866	(3,087)	(4,261)
Accounts payable	38,678	9,037	14,007
Accrued liabilities	30,629	20,398	18,874
Deferred revenue	176,126	90,340	47,564
Income taxes payable	42,650	32,018	4,377
Other liabilities	8,894	1,171	2,105
Interest payable	0	0	(960)
Net cash provided by operating activities	131,440	200,533	131,875
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from marketable securities	137,855	208,200	0
Purchases of marketable securities	(439,711)	0	(210,019)
Purchases of property and equipment	(21,419)	(19,989)	(13,134)
Other investing activities	(2,500)	0	(38,249)
Proceeds from repayment of notes receivable	0	0	8,000
Change in restricted cash	(204)	(4,041)	4,040
Net cash provided by (used in) investing activities	(325,979)	184,170	(249,362)
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments of lease financing obligations	(1,336)	(1,086)	(793)
Proceeds from issuance of common stock upon exercising options, net of repurchases	24,855	17,835	8,020
Minimum tax withholding paid on behalf of employees for net share settlement	(1,100)	0	0
Proceeds from issuance of common stock, employee stock purchase plan	10,326	9,366	0
Excess tax benefit on stock-based compensation	42,855	37,251	17,436
Proceeds from initial public offering, net of issuance cost	0	(261)	239,315
Repayment on notes payable	0	0	(20,000)
Net cash provided by financing activities	75,600	63,105	243,978
Effect of exchange rate changes	(464)	(513)	(124)
NET INCREASE/(DECREASE) IN CASH AND CASH EQUIVALENTS	(119,403)	447,295	126,367
CASH AND CASH EQUIVALENTS—Beginning of year	687,326	240,031	113,664
CASH AND CASH EQUIVALENTS—End of year	567,923	687,326	240,031
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for income taxes, net of refunds	39,638	6,591	44,770
Cash paid for interest— lease financing obligation	2,916	2,999	2,809
Cash paid for interest— notes payable	0	0	3,639
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:
Property and equipment included in accounts payable and accrued liabilities	869	3,957	1,638
Vesting of early exercised stock options and restricted stock awards	1,082	2,226	4,095
Acquisition of building with financing obligation	0	0	456
Unpaid deferred offering costs	0	0	261
Convertible Preferred Stock
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:
Conversion of stock upon initial public offering	0	0	5,992
Convertible Notes Payable
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:
Conversion of stock upon initial public offering	0	0	66,338
Convertible notes payable—related party
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:
Conversion of stock upon initial public offering	$ 0	$ 0	$ 30,153