CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating activities:
Net loss	$ (1,127,874)	$ (562,683)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	23,961	11,133
Share-based compensation expenses	134,020	95,812
Unrealized gains on equity method investments	(9,974)	0
Gain on deconsolidation of a subsidiary	(11,307)	0
Acquired in-process research and development	89,500	49,000
Amortization of research and development cost share liability	(85,296)	0
Deferred income tax benefits	(8,762)	(13,334)
Other items, net	1,144	(2,733)
Changes in operating assets and liabilities:
Accounts receivable	10,497	(14,856)
Inventories	(6,972)	(21,270)
Prepaid expenses and other current assets	(52,941)	(5,653)
Operating lease right-of-use assets	(5,207)	(4,303)
Other non-current assets	(5,980)	(15,307)
Accounts payable	21,979	(8,151)
Accrued expenses and other payables	115,872	33,494
Tax payable	(12,272)	3,173
Deferred revenue	0	(27,982)
Operating lease liabilities	5,312	2,072
Other long-term liabilities	(26,827)	(1,500)
Net cash used in operating activities	(951,127)	(483,088)
Investing activities:
Purchases of property, plant and equipment	(82,819)	(74,148)
Deconsolidation of a subsidiary	(2,025)	0
Purchases of investments	(4,879,705)	(850,825)
Proceeds from sale or maturity of investments	1,972,608	1,552,028
Purchase of in-process research and development	(89,500)	(49,000)
Net cash (used in) provided by investing activities	(3,081,441)	578,055
Financing activities:
Proceeds from sale of ordinary shares, net of cost	4,232,017	0
Proceeds from research and development cost share liability	616,834	0
Capital contribution from noncontrolling interest	0	4,000
Prepayment to acquire joint venture ("JV") minority interest	(28,723)	0
Proceeds from long-term loans	64,288	67,489
Repayment of long-term loans	(132,061)	(8,394)
Proceeds from short-term loans	48,983	0
Proceeds from option exercises and employee share purchase plan	75,830	20,387
Net cash provided by financing activities	4,877,168	83,482
Effect of foreign exchange rate changes, net	4,340	(18,339)
Net increase in cash, cash equivalents, and restricted cash	848,940	160,110
Cash, cash equivalents, and restricted cash at beginning of period	620,775	740,713
Cash, cash equivalents, and restricted cash at end of period	1,469,715	900,823
Supplemental cash flow information:
Cash and cash equivalents	1,464,470	856,851
Short-term restricted cash	295	14,271
Long-term restricted cash	4,950	30,401
Income taxes paid	10,596	8,951
Interest paid	41,577	3,335
Supplemental non-cash information:
Acquisitions of equipment included in accounts payable	$ 30,926	$ 29,255