CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 163,309	$ 161,833
Accounts receivable, net	25,081	20,562
Inventories, net	30,577	26,519
Available-for-sale securities	65,051	134,826
Prepaid research and development expenses	2,656	3,881
Other current assets	14,671	18,847
Total current assets	301,345	366,468
Inventories	87,267	98,053
Deposit on inventory	24,723	12,350
Property and equipment, net	14,285	15,287
Right-of-use assets, net	26,550	28,141
Intangible assets, net	61,708	62,920
Goodwill	63,074	63,074
Other assets	22,841	23,311
Total assets	601,793	669,604
Current liabilities:
Accounts payable	36,201	32,237
Accrued research and development expenses	46,573	53,214
Lease liabilities	5,389	5,405
Other accrued expenses	34,060	42,228
Total current liabilities	122,223	133,084
Long-term lease liabilities - less current portion	27,734	29,479
Convertible senior notes	524,905	644,751
Borrowings under financing agreement	52,419	34,991
Other long-term liabilities	1,506	1,556
Total liabilities	728,787	843,861
Commitments and contingencies (Note 13)
Stockholders' equity:
Preferred stock, par value $0.001 per share; 10,000,000 shares authorized, no shares issued and outstanding at March 31, 2020 and December 31, 2019
Common stock, $0.001 par value per share, 200,000,000 shares authorized at March 31, 2020 and December 31, 2019, respectively; 73,496,587 and 54,956,341 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively	73	55
Additional paid-in capital	2,260,671	2,114,068
Accumulated other comprehensive loss	(44,890)	(44,865)
Accumulated deficit	(2,342,848)	(2,243,515)
Total stockholders' deficit	(126,994)	(174,257)
Total liabilities and stockholders' equity (deficit)	$ 601,793	$ 669,604