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Nature of Business and Basis of Presentation (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Sep. 30, 2025 subsidiary	Dec. 31, 2026 £ / shares	Dec. 31, 2026 USD ($) $ / shares shares	Jun. 30, 2026 £ / shares	Jun. 30, 2026 USD ($)	Dec. 31, 2025 £ / shares	Dec. 31, 2025 USD ($)	Sep. 29, 2025	Jun. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)
Share Repurchase Program [Line Items]
Number of new subsidiaries | subsidiary	2
Ordinary shares, nominal value (per share) | £ / shares				£ 0.000025		£ 0.000025
Merger agreement extension period								60 days
Cash, cash equivalents and restricted cash | $					$ 59,630		$ 71,852		$ 87,784	$ 112,400
Accumulated deficit | $					$ 320,208		$ 304,092
Forecast
Share Repurchase Program [Line Items]
Ordinary shares, nominal value (per share) | £ / shares		£ 0.000025
Number of depositary shares per share of common stock (in shares) | shares			1
Scheme Shares | Minimum | Forecast
Share Repurchase Program [Line Items]
Stock conversion ratio			0.1
Scheme Shares | Maximum | Forecast
Share Repurchase Program [Line Items]
Stock conversion ratio			0.166667
Clywedog Capital Stock | Minimum | Forecast
Share Repurchase Program [Line Items]
Stock conversion ratio			0.000305
Clywedog Capital Stock | Maximum | Forecast
Share Repurchase Program [Line Items]
Stock conversion ratio			0.000508
Topco | Forecast
Share Repurchase Program [Line Items]
Ordinary shares, nominal value (per share) | $ / shares			$ 0.0001
Self-tender offer authorized amount to purchase | $			$ 27,000
Clywedog | Forecast
Share Repurchase Program [Line Items]
Ordinary shares, nominal value (per share) | $ / shares			$ 0.0001
Preferred stock par value (in dollars per share) | $ / shares			$ 0.0001

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