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	$ 1,477,529	$ 218,990
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred taxes	(1,504,251)	5,606
Depreciation and amortization	44,283	37,488
Stock-based compensation	47,934	43,511
Non-cash operating lease cost	11,148	8,681
Allowance for doubtful accounts	12,578	3,240
Impairments on equity investments	3,787	3,975
Impairments on long-lived assets	0	28,498
Gain from sale of equity method investment	0	(15,769)
Equity in losses of investee	0	7,528
Other non-cash operating activities	11,542	9,548
Changes in assets and liabilities, net of effects of acquisition:
Accounts receivable	64,645	(89,055)
Inventories	(21,398)	(26,681)
Prepaid expenses and other assets	(31,058)	(48,949)
Accounts payable	11,918	1,847
Accrued and other long-term liabilities	(106,572)	1,321
Long-term income tax payable	6,707	9,608
Deferred revenues	40,892	95,174
Net cash provided by operating activities	69,684	294,561
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition, net of cash acquired	(420,788)	0
Purchase of property, plant and equipment	(80,502)	(80,598)
Purchase of marketable securities	(5,341)	(353,995)
Proceeds from maturities of marketable securities	42,641	107,021
Proceeds from sales of marketable securities	278,817	14,456
Repayment on unsecured promissory note	11,087	6,598
Other investing activities	1,760	(14,502)
Net cash used in investing activities	(172,326)	(321,020)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	10,662	9,614
Common stock repurchases	0	(99,504)
Payroll taxes paid upon the vesting of equity awards	(47,038)	(52,718)
Purchase of finance lease	0	(45,773)
Net cash used in financing activities	(36,376)	(188,381)
Effect of foreign exchange rate changes on cash, cash equivalents, and restricted cash	(7,172)	1,467
Net decrease in cash, cash equivalents, and restricted cash	(146,190)	(213,373)
Cash, cash equivalents, and restricted cash at beginning of the period	551,134	637,566
Cash, cash equivalents, and restricted cash at end of the period	$ 404,944	$ 424,193