Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income		$ 144,538	$ 82,961
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other		5,697	4,939
Stock-based compensation		20,851	16,439
Deferred income taxes		(3,541)	2,521
Amortization (accretion) of investment premiums (discounts)		(30)	330
Changes in operating assets and liabilities:
Accounts receivable, net		40,007	44,057
Inventories		38,067	(50,296)
Prepaid expenses and other current assets		13,722	(29,051)
Other assets		(2,027)	69
Accounts payable		20,040	(18,648)
Accrued liabilities		(48,140)	(15,143)
Deferred revenue		(42,686)	124,236
Income taxes payable		3,478	2,923
Other liabilities		5,565	(2,475)
Net cash provided by operating activities		195,541	162,862
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities of marketable securities		90,448	64,488
Purchases of marketable securities		(267,976)	(61,511)
Purchases of property and equipment		(6,336)	(4,645)
Net cash used in investing activities	[1]	(183,864)	(1,668)
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments of lease financing obligations		(456)	(383)
Proceeds from issuance of common stock under equity plans		17,300	19,481
Tax withholding paid on behalf of employees for net share settlement		(1,536)	(580)
Net cash provided by financing activities		15,308	18,518
Effect of exchange rate changes		(14)	184
NET INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH		26,971	179,896
CASH, CASH EQUIVALENTS AND RESTRICTED CASH —Beginning of period		864,697	572,168
CASH, CASH EQUIVALENTS AND RESTRICTED CASH —End of period	[2]	891,668	752,064
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING INFORMATION:
Property and equipment included in accounts payable and accrued liabilities		$ 2,426	$ 971

[1] Net cash used in investing activites for the three monhts ended March 31, 2017 was adjusted as a result of our adoption of Accounting Standards Update 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash, in the first quarter of 2018. See Note 1 of the accompanying notes for details of the adjustments.

[2] See Note 3 of the accompanying notes for a reconciliation of the ending balance of cash, cash equivalents and restricted cash as shown in this statements of cash flows.