Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income		$ 283,224	$ 390,280
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other		21,170	16,757
Stock-based compensation		60,478	48,588
Noncash lease expense		8,223	7,955
Deferred income taxes		2,668	7,914
Gain on investments in privately-held companies		0	(1,150)
Amortization (accretion) of investment premiums (discounts)		2,938	(4,260)
Changes in operating assets and liabilities:
Accounts receivable, net		15,263	(11,303)
Inventories		(82,891)	(49,620)
Prepaid expenses and other current assets		26,815	48,864
Other assets		5,360	(4,635)
Accounts payable		31,473	(6,783)
Accrued liabilities		(39,882)	(9,476)
Deferred revenue		(19,242)	(85,009)
Income taxes payable		16,820	14,399
Other liabilities		646	3,955
Net cash provided by operating activities		333,063	366,476
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities of marketable securities		875,213	552,512
Purchases of marketable securities		(1,236,477)	(549,383)
Business acquisitions, net of cash acquired		(66,317)	0
Purchases of property and equipment		(5,178)	(8,639)
Net cash used in investing activities		(432,759)	(5,510)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock under equity plans		22,228	38,104
Tax withholding paid on behalf of employees for net share settlement		(4,000)	(4,662)
Repurchase of common stock		(227,895)	(100,008)
Net cash provided used in financing activities		(209,667)	(66,566)
Effect of exchange rate changes		(1,663)	72
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH		(311,026)	294,472
CASH, CASH EQUIVALENTS AND RESTRICTED CASH —Beginning of period		1,115,515	654,164
CASH, CASH EQUIVALENTS AND RESTRICTED CASH —End of period	[1]	804,489	948,636
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:
Right-of-use assets recognized upon the adoption of ASC 842		0	93,207
Right-of-use assets obtained in exchange for new operating lease liabilities		0	9,130
Property and equipment included in accounts payable and accrued liabilities		$ 788	$ 1,376

[1] See Note 4 of the accompanying notes for a reconciliation of the ending balance of cash, cash equivalents and restricted cash as shown in these condensed consolidated statements of cash flows.