CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 200,481	$ 62,436
Available-for-sale debt securities, at fair value (amortized cost $254,655, allowance for credit losses of $0 as of September 30, 2020; amortized cost $335,206, allowance for credit losses of $0 as of December 31, 2019)	255,786	336,088
Accounts receivable, net	15,025	18,048
Inventory, net	7,259	6,082
Prepaid expenses and other current assets	5,516	5,015
Tax receivable	13,615	1,395
Total current assets	497,682	429,064
Property and equipment, net	5,696	2,891
Other non-current assets	33,689	14,709
Intangible assets, net	154,217	157,200
Goodwill	936	936
Total assets	692,220	604,800
Current liabilities:
Accounts payable	9,431	26,614
Accrued expenses	50,320	51,745
Other current liabilities	6,775	8,590
Business combination-related contingent consideration, current portion	8,900	8,500
Total current liabilities	75,426	95,449
Convertible debt	212,651	204,861
Other non-current liabilities	40,330	20,894
Business combination-related contingent consideration, less current portion	62,400	62,400
Total liabilities	390,807	383,604
Stockholders' Equity:
Preferred stock $0.0001 par value; 20,000,000 shares authorized; 0 issued and outstanding as of September 30, 2020 and December 31, 2019	0	0
Common stock $0.0001 par value; 100,000,000 shares authorized; 51,023,187 and 43,088,921 issued and outstanding as of September 30, 2020 and December 31, 2019, respectively	5	4
Additional paid-in capital	765,307	636,910
Accumulated deficit	(464,253)	(416,444)
Accumulated other comprehensive income	354	726
Total stockholders' equity	301,413	221,196
Total liabilities and stockholders' equity	$ 692,220	$ 604,800