Stock-Based Compensation Plans - Schedule of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2025 USD ($) $ / shares shares	Dec. 31, 2024 USD ($) $ / shares shares
Number of Options
Beginning balance (in shares) | shares	8,537,210
Options granted (in shares) | shares	2,317,260
Options exercised (in shares) | shares	(487,890)
Options canceled (in shares) | shares	(359,760)
Ending balance (in shares) | shares	10,006,820	8,537,210
Vested and exercisable (in shares) | shares	3,892,199
Vested and expected to vest (in shares) | shares	10,006,820
Awards Weighted-Average Exercise Price
Beginning balance (in dollar per share) | $ / shares	$ 4.72
Options granted (in dollars per share) | $ / shares	17.79
Options exercised (in dollars per share) | $ / shares	4.98
Options canceled (in dollars per share) | $ / shares	6.24
Ending balance (in dollar per share) | $ / shares	7.68	$ 4.72
Vested and exercisable (in dollar per share) | $ / shares	5.24
Vested and expected to vest (in dollar per share) | $ / shares	$ 7.68
Stock Options Additional Disclosures
Weighted-Average Remaining Contractual Life (Years)	8 years 3 days	7 years 11 months 15 days
Vested and exercisable weighted-average remaining contractual life (in years)	6 years 8 months 12 days
Vested and expected to vest weighted-average remaining contractual life (in years)	8 years 3 days
Aggregate Intrinsic Value | $	$ 260,007	$ 68,256
Vested and exercisable aggregate intrinsic value | $	110,604
Vested and expected to vest aggregate intrinsic value | $	$ 260,007