Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating activities:
Net income (loss)	$ 446,575	$ (184,480)
Adjustments to reconcile net income (loss) to net cash provided (used) by operating activities
Share-based compensation	107,458	79,747
Depreciation	26,219	17,885
Amortization of intangible assets	10,541	11
Amortization of right-of-use assets	7,945	7,257
Amortization of premiums, accretion of discounts, and (gains) losses on debt securities	(426)	(3,750)
(Gains) losses on equity securities	(11,604)	10,258
Changes in operating assets and liabilities
Accounts receivable, net	(57,166)	(44,037)
Inventories	(10,795)	(38,795)
Prepaid expenses and other assets	(16,792)	3,414
Lease liability	(8,223)	(4,633)
Deferred revenue	300	(26,572)
Other liabilities	173,392	31,809
Net cash provided (used) by operating activities	667,424	(151,886)
Investing activities:
Purchases of securities	(811,274)	(666,120)
Proceeds from maturities of securities	587,000	375,000
Proceeds from sales of securities	194,733	0
Purchases of property and equipment	(65,899)	(51,763)
Net cash used by investing activities	(95,440)	(342,883)
Financing activities:
Net proceeds from issuance of common stock	0	548,691
Proceeds from exercise of stock options and employee stock purchase plan	72,773	61,358
Net cash provided by financing activities	72,773	610,049
Effect of exchange rate changes on cash and cash equivalents	135	0
Net increase in cash and cash equivalents	644,892	115,280
Cash and cash equivalents at beginning of period	274,562	78,186
Cash and cash equivalents at end of period	$ 919,454	$ 193,466