CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net income (loss)	$ (28,844)	$ 92,105
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	225	348
Noncash lease expense	362	197
Loss from equity method investment	2,802	591
Stock-based compensation expense	2,369	4,051
(Accretion of discount) amortization of premium on short-term investments	(909)	38
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	2,431	507
Accounts payable	2,491	7,701
Accrued expenses and other liabilities	(5,815)	(4,988)
Accrued income taxes	0	967
Deferred revenue	(802)	(802)
Operating lease liabilities	(375)	(150)
Net cash used in operating activities	(26,054)	(30,684)
Cash flows from investing activities:
Purchases of short-term investments	(25,283)	0
Sales of marketable securities	56,883	0
Maturities of short-term investments	0	39,461
Proceeds from sale of business	0	130,000
Purchases of property and equipment	(228)	(1,149)
Net cash provided by (used in) investing activities	31,372	168,312
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	0	1
Net cash provided by financing activities	150	440
Net change in cash, cash equivalents and restricted cash	5,468	138,068
Cash, cash equivalents and restricted cash, beginning of period	33,986	110,335
Cash, cash equivalents and restricted cash, end of period	39,454	248,403
Supplemental disclosures of noncash investing and financing activities:
Property and equipment additions included in accounts payable	0	59
Property and equipment additions included in accrued expenses and other liabilities	0	5
Unrealized loss on available for sale securities, net	$ 222	$ 7