CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities
Net income (loss)	$ (3,856)	$ 18,303
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation of property and equipment	634	688
Stock-based compensation	8,608	7,649
Amortization of premiums and accretion of discounts on marketable securities	(2)	1,016
Gain on sale of marketable securities	0	(12)
Intangible asset amortization	758	739
Deferred income taxes	2,550	2,906
Other non-cash adjustments, net	975	666
Changes in operating assets and liabilities:
Accounts receivable	3,575	(7,064)
Prepaid expenses and other assets	(13,691)	(1,554)
Inventory	(1,582)	(1,366)
Accounts payable and other liabilities	13,732	888
Product revenue allowances	(1,970)	5,351
Net cash provided by operating activities	9,731	28,210
Cash flows from investing activities
Purchases of property and equipment	(268)	(428)
Purchases of marketable securities	(175,985)	(197,352)
Sales and maturities of marketable securities	172,527	163,670
Net cash used in investing activities	(3,726)	(34,110)
Cash flows from financing activities
Proceeds from exercise of stock options	125	2,138
Net cash provided by financing activities	125	2,138
Effect of exchange rate changes on cash, cash equivalents and restricted cash	22	(29)
Net change in cash, cash equivalents and restricted cash	6,152	(3,791)
Cash, cash equivalents and restricted cash
Beginning of period	52,590	61,613
End of period	$ 58,742	$ 57,822