Income Taxes - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Rate
Income tax computed at federal statutory tax rate	21.00%	21.00%
State taxes, net of federal benefit	(0.12%)	6.70%
Research and Development credit	2.45%
Change in valuation allowance	(22.86%)	(31.30%)
General business credit carryovers		4.10%
Stock compensation	(0.52%)
Other Nontaxable or nondeductible items	(0.04%)
Permanent differences		(0.50%)
Other	(0.06%)	0.10%
Total	(0.15%)	0.00%
Tax
At U.S. federal statutory rate	$ (28,924)
State taxes, net of federal benefit	165
Tax credits	(3,377)
Changes in valuation allowances	31,487
Stock compensation	712
Other Nontaxable or nondeductible items	59
Other items	95
Total tax expense	$ 217	$ 187
MASSACHUSETTS
Tax
Effective income tax rate reconciliation, state and local jurisdiction, contribution greater than 50 percent	(98.00%)