UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024
Cash flows from operating activities
Net loss	$ (30,668)	$ (26,448)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,428	1,285
Amortization and accretion of investments, net	(992)	(1,839)
Noncash lease expense	992	849
Gain on disposal of assets, including assets held for sale	(585)	(1,078)
Share-based compensation	2,681	2,445
Carrying value adjustment to assets held for sale	1,590	5,564
Changes in operating assets and liabilities:
Accounts receivable	764	(333)
Prepaid expenses and other assets	1,920	(5,131)
Accounts payable	1,015	(3,239)
Accrued expenses and other liabilities	(1,962)	(4,427)
Operating lease liabilities	(1,182)	(1,044)
Net cash used in operating activities	(23,999)	(33,396)
Cash flows from investing activities
Purchase of property and equipment	(11,575)	(8,054)
Proceeds from sale of property and equipment	800	3,470
Receipt of security deposit	41	0
Purchase of investments	(18,397)	(32,623)
Proceeds from sale and maturity of investments	60,026	83,234
Net cash provided by investing activities	30,895	46,027
Cash flows from financing activities
Proceeds from exercise of common stock options	0	50
Taxes paid related to net share settlement of equity awards	(532)	(365)
Repurchase of treasury stock	0	(13,982)
Net cash used in financing activities	(532)	(14,297)
Net increase (decrease) in cash and cash equivalents and restricted cash	6,364	(1,666)
Cash and cash equivalents and restricted cash, beginning of period	9,892	21,464
Cash and cash equivalents and restricted cash, end of period	16,256	19,798
Supplemental disclosure of noncash investing and financing activities:
Repurchase of treasury stock included in accrued expenses	0	126
Acquisitions of property and equipment included in accounts payable and accrued expenses and other current liabilities	$ 447	$ 150