CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 84,477	$ 31,269
Short-term marketable securities	222,838	244,693
Trade receivables, net of allowances	26,684	19,928
Inventory	5,084	5,424
Prepaid expenses and other current assets	5,693	6,044
Total current assets	344,776	307,358
Strategic inventory	11,063	11,981
Operating lease right-of-use asset	3,082	3,446
Property and equipment, net of accumulated depreciation	880	1,050
Long-term marketable securities	41,690	39,352
Other assets	3,441	3,448
Deferred tax assets, net	40,562	45,677
Total assets	445,494	412,312
Current liabilities:
Accounts payable	4,976	7,537
Accrued clinical expenses	7,938	6,477
Accrued and other liabilities	19,590	23,269
Short-term operating lease liability	1,571	1,558
Total current liabilities	34,075	38,841
Long-term operating lease liability	1,541	1,903
Long-term accrued income taxes	389	386
Total liabilities	36,005	41,130
Stockholders’ equity:
Preferred stock	0	0
Common stock	120	120
Additional paid-in capital	465,528	457,060
Treasury stock	(62,979)	(62,704)
Accumulated other comprehensive income	310	261
Retained earnings (accumulated deficit)	6,510	(23,555)
Total stockholders’ equity	409,489	371,182
Total liabilities and stockholders’ equity	$ 445,494	$ 412,312