Redeemable Convertible Preferred Stock - Narrative (Details) $ / shares in Units, $ in Thousands			3 Months Ended		9 Months Ended
	Jun. 20, 2025 $ / shares shares	Apr. 01, 2025 USD ($) $ / shares shares	Sep. 30, 2025 USD ($) $ / shares shares	Sep. 30, 2024 USD ($) shares	Sep. 30, 2025 USD ($) $ / shares shares	Sep. 30, 2024 USD ($) shares	Jun. 30, 2025 shares	Mar. 31, 2025 $ / shares	Dec. 31, 2024 $ / shares shares	Jun. 30, 2024 shares	Dec. 31, 2023 shares
Temporary Equity [Line Items]
Temporary equity outstanding (in shares) | shares	751,145,116			734,142,041		734,142,041	0		734,142,041	734,142,041	734,142,041
Proceeds from issuance of preferred stock, net of issuance costs | $		$ 137,700
Payments of stock issuance costs | $					$ 7,710	$ 1,034
Temporary equity, dividends, adjustment | $			$ 0	$ 0	$ 384,436	0
Common Stock
Temporary Equity [Line Items]
Conversion of preferred stock to common stock, including the derecognition of associated embedded derivatives (in shares) | shares	211,378,638				211,378,638
Redeemable Convertible Preferred Stock
Temporary Equity [Line Items]
Temporary equity outstanding (in shares) | shares			0		0
Series E & Series F Convertible Preferred Stock
Temporary Equity [Line Items]
Preferred stock, dividend rate, percentage		8.00%
Conversion price, percent of initial public offering per share price	70.00%	70.00%
Series E & Series F Convertible Preferred Stock | Preferred Stock Purchase Agreement
Temporary Equity [Line Items]
Proceeds from issuance of preferred stock, net of issuance costs | $		$ 137,700
Payments of stock issuance costs | $		$ 6,800
Series E Convertible Preferred Stock
Temporary Equity [Line Items]
Shares issued, price per share (in dollars per share)		$ 8.10
Series E Convertible Preferred Stock | Preferred Stock Purchase Agreement
Temporary Equity [Line Items]
Sale of stock, number of shares issued in transaction (in shares) | shares		12,345,674
Sale of stock, price per share (in dollars per share)			$ 8.10		$ 8.10
Series F Convertible Preferred Stock
Temporary Equity [Line Items]
Shares issued, price per share (in dollars per share)		$ 8.10
Series F Convertible Preferred Stock | Preferred Stock Purchase Agreement
Temporary Equity [Line Items]
Sale of stock, number of shares issued in transaction (in shares) | shares		4,657,401
Sale of stock, price per share (in dollars per share)									$ 8.10
Series C Preferred Stock
Temporary Equity [Line Items]
Temporary equity outstanding (in shares) | shares	116,200,835		0		0				116,200,835
Preferred stock, dividend rate, percentage					7.00%
Original issue price per share (in dollars per share)	$ 2.76	$ 4.58						$ 2.76
Shares issued, price per share (in dollars per share)	$ 2.76	$ 4.58						$ 2.76	$ 2.76
Initial public offering, conversion price ratio, minimum	1.11111
Initial public offering, reduction in conversion price, percent of purchase price	90.00%
Series D Preferred Stock
Temporary Equity [Line Items]
Temporary equity outstanding (in shares) | shares	102,516,283		0		0				102,516,283
Preferred stock, dividend rate, percentage					7.00%
Temporary equity, liquidation preference, ratio			1.2		1.2
Original issue price per share (in dollars per share)	$ 8.10
Shares issued, price per share (in dollars per share)	$ 8.10								$ 8.10
Initial public offering, conversion price ratio, minimum			1.11111		1.11111
Temporary equity, dividends, adjustment | $					$ 384,400
Initial public offering, reduction in conversion price, percent of purchase price	90.00%
Initial public offering, percent of stock conversion price, minimum	110.00%
Series A Preferred Stock
Temporary Equity [Line Items]
Temporary equity outstanding (in shares) | shares	485,795,293		0		0				485,795,293
Original issue price per share (in dollars per share)	$ 0.61
Shares issued, price per share (in dollars per share)	$ 0.61								$ 0.61
Series B Preferred Stock
Temporary Equity [Line Items]
Temporary equity outstanding (in shares) | shares	29,629,630		0		0				29,629,630
Original issue price per share (in dollars per share)	$ 0.54
Shares issued, price per share (in dollars per share)	$ 0.54								$ 0.54
Series E Preferred Stock
Temporary Equity [Line Items]
Temporary equity outstanding (in shares) | shares	12,345,674
Proceeds from issuance of preferred stock, net of issuance costs | $					$ 87,637	0
Preferred stock, dividend rate, percentage					7.00%
Original issue price per share (in dollars per share)	$ 8.10
Shares issued, price per share (in dollars per share)	$ 8.10
Series F Preferred Stock
Temporary Equity [Line Items]
Temporary equity outstanding (in shares) | shares	4,657,401
Proceeds from issuance of preferred stock, net of issuance costs | $					$ 33,601	$ 0
Preferred stock, dividend rate, percentage					8.00%
Temporary equity, liquidation preference, ratio			1.5		1.5
Original issue price per share (in dollars per share)	$ 8.10
Shares issued, price per share (in dollars per share)	$ 8.10