Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income		$ 138,431	$ 201,029
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other		10,208	8,362
Stock-based compensation		27,556	24,291
Noncash lease expense		4,073	3,689
Deferred income taxes		457	(718)
(Gain) loss on investments in privately-held companies		0	(1,150)
Amortization (accretion) of investment premiums (discounts)		1,042	(2,069)
Changes in operating assets and liabilities:
Accounts receivable, net		46,329	60,531
Inventories		(17,691)	(82,596)
Prepaid expenses and other current assets		25,751	30,664
Other assets		3,946	(2,475)
Accounts payable		(6,386)	(2,391)
Accrued liabilities		(39,450)	(19,014)
Deferred revenue		21	(50,756)
Income taxes payable		3,982	2,040
Other liabilities		(3,422)	660
Net cash provided by operating activities		194,847	170,097
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities of marketable securities		414,503	302,264
Purchases of marketable securities		(674,649)	(332,247)
Business acquisitions, net of cash acquired		(66,225)	0
Purchases of property and equipment		(3,107)	(5,237)
Net cash used in investing activities		(329,478)	(35,220)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock under equity plans		17,082	26,323
Tax withholding paid on behalf of employees for net share settlement		(1,740)	(1,850)
Repurchase of common stock		(227,895)	0
Net cash provided by (used in) financing activities		(212,553)	24,473
Effect of exchange rate changes		(2,691)	195
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH		(349,875)	159,545
CASH, CASH EQUIVALENTS AND RESTRICTED CASH —Beginning of period		1,115,515	654,164
CASH, CASH EQUIVALENTS AND RESTRICTED CASH —End of period	[1]	765,640	813,709
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	9,034
Property and equipment included in accounts payable and accrued liabilities		$ 524	$ 1,055

[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 this condensed consolidated statements of cash flows.