Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)		$ 390,280	$ (10,731)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, amortization and other		16,757	11,328
Stock-based compensation		48,588	43,329
Noncash lease expense		7,955	0
Deferred income taxes		7,914	(18,281)
(Gain) loss on investments in privately-held companies		(1,150)	9,100
Accretion of investment discounts		(4,260)	(783)
Changes in operating assets and liabilities:
Accounts receivable, net		(11,303)	(13,571)
Inventories		(49,620)	60,759
Prepaid expenses and other current assets		48,864	(72,418)
Other assets		(4,635)	629
Accounts payable		(6,783)	3,597
Accrued liabilities		(9,476)	(47,153)
Accrued legal settlement		0	405,000
Deferred revenue		(85,009)	(50,096)
Income taxes payable		14,399	6,653
Other liabilities		3,955	(1,237)
Net cash provided by operating activities		366,476	326,125
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from maturities of marketable securities		552,512	222,764
Purchases of marketable securities		(549,383)	(696,665)
Purchases of property and equipment		(8,639)	(13,071)
Investments in privately-held companies		0	(8,000)
Other investing activities		0	(2,000)
Net cash used in investing activities		(5,510)	(496,972)
CASH FLOWS FROM FINANCING ACTIVITIES:
Principal payments of lease financing obligations		0	(921)
Proceeds from issuance of common stock under equity plans		38,104	28,810
Tax withholding paid on behalf of employees for net share settlement		(4,662)	(4,463)
Repurchase of common stock		(100,008)	0
Net cash provided by (used in) financing activities		(66,566)	23,426
Effect of exchange rate changes		72	(607)
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH		294,472	(148,028)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH —Beginning of period		654,164	864,697
CASH, CASH EQUIVALENTS AND RESTRICTED CASH —End of period	[1]	948,636	716,669
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:
Right-of-use assets recognized upon the adoption of ASC 842	[2]	93,207	0
Right-of-use assets obtained in exchange for new operating lease liabilities		9,130	0
Property and equipment included in accounts payable and accrued liabilities		$ 1,376	$ 1,077

[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.

[2] See Note 1 of the accompanying notes.