CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net income (loss)	$ (63,888)	$ 63,016
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	442	676
Noncash lease expense	726	655
Loss from equity method investment	8,541	1,952
Stock-based compensation expense	4,771	7,194
(Accretion of discount) amortization of premium on short-term investments	(1,519)	(91)
Loss on disposal of property and equipment	11	0
Gain on sale of business	0	(131,249)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,724	(6,088)
Accounts payable	2,249	1,637
Accrued expenses and other liabilities	(862)	1,646
Accrued income taxes	0	862
Deferred revenue	(1,156)	(1,604)
Operating lease liabilities	(753)	(136)
Net cash used in operating activities	(49,714)	(61,530)
Cash flows from investing activities:
Purchases of short-term investments	(25,282)	(49,248)
Maturities of short-term investments	117,883	47,461
Proceeds from sale of business	0	130,000
Purchases of property and equipment	(228)	(1,270)
Net cash provided by investing activities	92,373	126,943
Cash flows from financing activities:
Proceeds from issuance of common stock pursuant to employee stock purchase plan	150	439
Proceeds from issuance of common stock from option exercises	2	1
Net cash provided by financing activities	152	440
Net change in cash, cash equivalents and restricted cash	42,811	65,853
Cash, cash equivalents and restricted cash, beginning of period	33,986	110,335
Cash, cash equivalents and restricted cash, end of period	76,797	176,188
Supplemental disclosures of noncash investing and financing activities:
Property and equipment additions included in accrued expenses and other liabilities	0	5
Unrealized loss on available for sale securities, net	$ 316	$ (34)