CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 442,776	$ 400,235	$ 231,418
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred taxes	307	(15,680)	17,572
Depreciation and amortization	78,990	54,727	37,739
Stock-based compensation	88,184	70,763	58,854
Non-cash operating lease cost	18,475
Impairments and other (gains) charges	28,498	0	0
Gain on lease terminations	(6,792)
Gain from sale of equity method investment	(15,769)	0	0
Equity in losses of investee	7,528	8,693	3,219
Other non-cash operating activities	29,860	17,252	13,847
Changes in assets and liabilities, net of effects of acquisitions:
Accounts receivable	(121,014)	(109,224)	(90,990)
Inventories	(58,269)	(24,109)	(5,481)
Prepaid expenses and other assets	(31,529)	(9,122)	(8,669)
Accounts payable	22,099	25,045	8,175
Accrued and other long-term liabilities	60,240	36,250	24,235
Long-term income tax payable	14,611	(36,548)	68,958
Deferred revenues	189,075	136,399	79,662
Net cash provided by operating activities	747,270	554,681	438,539
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property, plant and equipment	(149,707)	(223,312)	(195,695)
Purchase of marketable securities	(693,284)	(180,191)	(390,244)
Proceeds from maturities of marketable securities	290,754	375,105	349,240
Proceeds from sales of marketable securities	194,677	9,560	39,536
Repayment on unsecured promissory note	21,820	0	0
Purchases of investments in privately held companies	0	(5,000)	(12,764)
Loan advances to equity investee	0	0	(36,000)
Loan repayment from equity investee	0	30,000	6,000
Acquisition, net of cash acquired	0	0	(8,953)
Other investing activities	(14,704)	765	(2,597)
Net cash provided by (used in) investing activities	(350,444)	6,927	(251,477)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	17,907	16,635	14,461
Common stock repurchases	(399,999)	(300,002)	(103,793)
Payroll taxes paid upon the vesting of equity awards	(57,675)	(86,067)	(46,168)
Purchase of finance lease	(45,773)
Net cash used in financing activities	(485,540)	(369,434)	(135,500)
Effect of foreign exchange rate changes on cash, cash equivalents, and restricted cash	2,282	(4,733)	5,544
Net increase (decrease) in cash, cash equivalents, and restricted cash	(86,432)	187,441	57,106
Cash, cash equivalents, and restricted cash at beginning of year	637,566	450,125	393,019
Cash, cash equivalents, and restricted cash at end of the period	$ 551,134	$ 637,566	$ 450,125