CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating activities:
Net loss	$ (262,831)	$ (111,303)
Adjustments to reconcile net loss to net cash from operating activities:
Depreciation and amortization expense	4,580	1,404
Share-based compensation expenses	36,037	13,074
Acquired in-process research and development	10,000
Non-cash interest expense	4,115	2,232
Deferred income tax benefits	(8,413)	(4,059)
Other non-cash income	(2,336)	(3)
Changes in operating assets and liabilities:
Accounts receivable	(3,743)
Unbilled receivable	3,605
Inventories	4,608
Prepaid expenses and other current assets	(27,669)	(5,036)
Other non-current assets	(3,694)	(139)
Accounts payable	10,308	13,242
Accrued expenses and other payables	25,439	130
Tax payable	(8,005)	2,302
Deferred revenue	(3,442)
Other long-term liabilities	(197)	559
Net cash used in operating activities	(221,638)	(87,597)
Investing activities:
Purchases of property and equipment	(20,309)	(8,881)
Payment for the acquisition of land use right		(12,124)
Purchases of investments	(1,198,922)	(27,646)
Proceeds from sale or maturity of available-for-sale securities	869,011	161,900
Purchase of in-process research and development	(10,000)
Net cash (used in) provided by investing activities	(360,220)	113,249
Financing activities:
Proceeds from public offering, net of underwriter discount	758,001
Payment of public offering cost	(414)
Proceeds from long-term loan	42,315
Proceeds from short-term loan		2,470
Repayment of short-term loan		(2,470)
Capital contribution from noncontrolling interest		14,527
Proceeds from shareholder loan		132,757
Proceeds from option exercises	10,582	316
Net cash provided by financing activities	810,484	147,600
Effect of foreign exchange rate changes, net	1,783	240
Net increase in cash, cash equivalents, and restricted cash	230,409	173,492
Cash, cash equivalents, and restricted cash at beginning of period	239,602	87,514
Cash, cash equivalents, and restricted cash at end of period	470,011	261,006
Supplemental cash flow disclosures:
Cash and cash equivalents	438,420	261,006
Restricted Cash	31,591
Income taxes paid	11,842	746
Interest expense paid	667	618
Non-cash activities:
Acquisitions of equipment included in accounts payable	8,006	$ 1,373
Changes in operating assets and liabilities adjusted through accumulated deficit	$ 2,291