Redeemable Convertible Preferred Stock (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Jun. 30, 2025	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023
Temporary Equity [Line Items]
Shares Authorized (in shares)	29,544,989		29,544,989
Shares Issued (in shares)	29,084,235		29,084,235
Shares Outstanding (in shares)	29,084,235	29,084,235	29,084,235	29,084,235	29,084,235	22,701,179
Net Carrying Value	$ 419,409		$ 419,409
Aggregate Liquidation Preference	$ 422,458		$ 422,458
Series A-1
Temporary Equity [Line Items]
Shares Authorized (in shares)	1,349,650		1,349,650
Shares Issued (in shares)	1,349,650		1,349,650
Shares Outstanding (in shares)	1,349,650		1,349,650
Net Carrying Value	$ 3,493		$ 3,493
Aggregate Liquidation Preference	$ 540		$ 540
Series A-2
Temporary Equity [Line Items]
Shares Authorized (in shares)	1,137,210		1,137,210
Shares Issued (in shares)	1,137,210		1,137,210
Shares Outstanding (in shares)	1,137,210		1,137,210
Net Carrying Value	$ 2,943		$ 2,943
Aggregate Liquidation Preference	$ 910		$ 910
Series A-3
Temporary Equity [Line Items]
Shares Authorized (in shares)	899,730		899,730
Shares Issued (in shares)	899,730		899,730
Shares Outstanding (in shares)	899,730		899,730
Net Carrying Value	$ 2,328		$ 2,328
Aggregate Liquidation Preference	$ 900		$ 900
Series A-4
Temporary Equity [Line Items]
Shares Authorized (in shares)	25,761		25,761
Shares Issued (in shares)	25,761		25,761
Shares Outstanding (in shares)	25,761		25,761
Net Carrying Value	$ 67		$ 67
Aggregate Liquidation Preference	$ 50		$ 50
Series A-5
Temporary Equity [Line Items]
Shares Authorized (in shares)	114,613		114,613
Shares Issued (in shares)	114,613		114,613
Shares Outstanding (in shares)	114,613		114,613
Net Carrying Value	$ 297		$ 297
Aggregate Liquidation Preference	$ 100		$ 100
Series A-6
Temporary Equity [Line Items]
Shares Authorized (in shares)	5,805,861		5,805,861
Shares Issued (in shares)	5,796,201		5,796,201
Shares Outstanding (in shares)	5,796,201		5,796,201
Net Carrying Value	$ 14,999		$ 14,999
Aggregate Liquidation Preference	$ 15,000		$ 15,000
Series B-1
Temporary Equity [Line Items]
Shares Authorized (in shares)	5,182,287		5,182,287
Shares Issued (in shares)	5,182,287		5,182,287
Shares Outstanding (in shares)	5,182,287		5,182,287
Net Carrying Value	$ 54,889		$ 54,889
Aggregate Liquidation Preference	$ 55,000		$ 55,000
Series B-2
Temporary Equity [Line Items]
Shares Authorized (in shares)	2,566,902		2,566,902
Shares Issued (in shares)	2,566,902		2,566,902
Shares Outstanding (in shares)	2,566,902		2,566,902
Net Carrying Value	$ 27,243		$ 27,243
Aggregate Liquidation Preference	$ 16,025		$ 16,025
Series C
Temporary Equity [Line Items]
Shares Authorized (in shares)	6,079,919		6,079,919
Shares Issued (in shares)	5,628,825		5,628,825
Shares Outstanding (in shares)	5,628,825		5,628,825
Net Carrying Value	$ 143,268		$ 143,268
Aggregate Liquidation Preference	$ 143,500		$ 143,500
Series C-1
Temporary Equity [Line Items]
Shares Authorized (in shares)	1,726,823		1,726,823
Shares Issued (in shares)	1,726,823		1,726,823
Shares Outstanding (in shares)	1,726,823		1,726,823
Net Carrying Value	$ 39,886		$ 39,886
Aggregate Liquidation Preference	$ 33,870		$ 33,870
Series D
Temporary Equity [Line Items]
Shares Authorized (in shares)	4,656,233		4,656,233
Shares Issued (in shares)	4,656,233		4,656,233
Shares Outstanding (in shares)	4,656,233		4,656,233
Net Carrying Value	$ 129,996		$ 129,996
Aggregate Liquidation Preference	$ 156,563		$ 156,563