Shareholders’ Equity and Equity Compensation - Narrative (Details) $ / shares in Units, $ in Thousands							1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 20, 2025 $ / shares shares	May 23, 2025 shares	Mar. 03, 2025 USD ($) $ / shares shares	Aug. 11, 2022 grantee $ / shares shares	Feb. 23, 2022 shares	Nov. 09, 2021 shares	Aug. 31, 2025 USD ($) shares	Sep. 30, 2025 USD ($) vote $ / shares shares	Sep. 30, 2024 USD ($) shares	Sep. 30, 2025 USD ($) vote $ / shares shares	Sep. 30, 2024 USD ($) shares	Dec. 31, 2024 USD ($) $ / shares shares	Jun. 30, 2025 shares	Jun. 01, 2025 $ / shares	Jun. 30, 2024 shares	Dec. 31, 2023 shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Preferred stock authorized (in shares)	100,000,000							100,000,000		100,000,000		0
Preferred stock, par value (in dollars per share) | $ / shares	$ 0.001							$ 0.001		$ 0.001		$ 0.001
Preferred stock, outstanding (in shares)								0		0		0
Preferred stock, shares issued (in shares)								0		0		0
Common stock authorized (in shares)	2,800,000,000							2,800,000,000		2,800,000,000		1,150,000,000
Common stock, par value (in dollars per share) | $ / shares								$ 0.001		$ 0.001		$ 0.001		$ 0.001
Common stock, shares outstanding (in shares)								282,103,259		282,103,259		36,504,319
Vote per share of common stock (in votes) | vote								1		1
Treasury stock, shares, acquired (in shares)										1,438,138		0
Repurchases of common stock | $										$ 16,587
Treasury stock, shares (in shares)								1,620,638		1,620,638		182,500
Treasury stock reissued (in shares)										0		0
Exercised | $								$ 8,700	$ 1,100	$ 13,500	$ 2,600
Granted (in shares)			1,530,000							3,085,295
Granted (in dollars per share) | $ / shares			$ 18.60							$ 18.79
Exercised (in shares)										1,287,294
Related party promissory note receivable (see note 7) | $								0		$ 0		$ 26,456
Share-based payment arrangement, expense | $								$ 13,655	$ 4,723	$ 56,639	$ 13,666
Employee Stock
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Maximum percent of aggregate number of outstanding shares, on last day of immediately preceding fiscal year	1.00%
Share-based compensation arrangement by share-based payment award, number of shares authorized (in shares)	2,571,250
Share-based compensation arrangement, purchase price of common stock, percent (in percentage)	85.00%
Outstanding stock options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period										5 years
Expiration period										10 years
Exercise price of each option, threshold, percentage of fair value of common stock								100.00%		100.00%
Unrecognized compensation cost, options | $			$ 5,700					$ 58,600		$ 58,600
Unrecognized compensation cost, weighted-average period										3 years 1 month 2 days
Granted (in shares)								0
Risk-free interest rate, minimum (in percent)			3.93%							3.90%	3.70%
Risk-free interest rate, maximum (in percent)			3.99%							4.20%	4.60%
Expected dividend yield (in percent)			0.00%						0.00%	0.00%	0.00%
Expected volatility rate, minimum (in percent)			68.96%						68.20%	68.30%	62.50%
Expected volatility rate, maximum (in percent)			69.48%						68.40%	69.50%	68.40%
Total incremental fair value | $			$ 15,100
Share-based payment arrangement, expense | $			8,600
Portion remaining after compensation expense | $			$ 6,500
Outstanding stock options | Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)			5 years						6 years 4 months 2 days	5 years	5 years 11 months 19 days
Outstanding stock options | Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expected term (in years)			5 years 3 months 18 days						6 years 6 months 25 days	6 years 6 months 18 days	6 years 6 months 25 days
Prior Stock Options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period										5 years
Granted (in shares)					2,000,000	331,250
Granted (in dollars per share) | $ / shares				$ 16.20
Number of grantees | grantee				5
Exercised (in shares)				1,530,000
Prior Stock Options | Share-Based Payment Arrangement, Tranche One
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting percent				20.00%
Prior Stock Options | Share-Based Payment Arrangement, Tranche Two
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period				4 years
New Stock Options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Repurchase rights period										4 years
Options exercised in period, subject to repurchase (in shares)										23,446		662,000
Options exercised in period, subject to repurchase | $ / shares								$ 16.20		$ 16.20
Options exercised, subject to repurchase, current | $								$ 300		$ 300		$ 5,000
Options exercised, subject to repurchase, noncurrent | $								100		$ 100		$ 5,800
Early Exercised Stock Options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Treasury stock, shares, acquired (in shares)			1,429,213
Stock repurchase price per share (in dollars per share) | $ / shares			$ 18.60
Vested, outstanding shares (in shares)			810,816
Unvested (in shares)			618,397
Unvested RSUs
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting period										4 years
Unrecognized compensation cost, weighted-average period										3 years 6 months 7 days
Equity instruments other than options, settled during period (in shares)							1,048,250
Common stock withheld for taxes and net exercises (in shares)							415,389
Tax withholding liability | $							$ 12,400
Unrecognized stock-based compensation cost | $								$ 85,300		$ 85,300
2020 Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)								22,906,854		22,906,854
2025 Incentive Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (in shares)								4,132,565		4,132,565
Common stock, capital shares reserved for future issuance, initial amount authorized		15,125,002
Maximum percent of aggregate number of outstanding shares, on last day of immediately preceding fiscal year		4.00%
Common Stock
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock, shares outstanding (in shares)								282,103,259	35,815,819	282,103,259	35,815,819	35,842,319	281,090,538		35,418,384	35,297,278
Treasury stock, shares, acquired (in shares)										1,438,138
Exercised (in shares)								600,133	91,435	1,948,254	212,541
Common Stock | Outstanding stock options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock withheld for taxes and net exercises (in shares)								220,273		355,232
Common Stock | Unvested RSUs
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Common stock withheld for taxes and net exercises (in shares)								415,389		415,389