Shareholders' Equity (Details) $ in Millions		6 Months Ended		21 Months Ended	34 Months Ended
	Oct. 08, 2021 USD ($)	Jun. 30, 2023 £ / shares shares	Jun. 30, 2022 £ / shares shares	Jun. 30, 2023 USD ($) shares	Jun. 30, 2023 USD ($) shares	Jun. 30, 2023 USD ($) shares	Mar. 31, 2023 £ / shares	Dec. 31, 2022 £ / shares	Mar. 31, 2022 £ / shares	Dec. 31, 2021 £ / shares	Sep. 30, 2020 £ / shares	Aug. 31, 2020 £ / shares
Class of Stock [Line Items]
Ordinary share conversion ratio	1
Exercise of share options (in shares)		128,869
Number of shares available for purchase, percent of principal amount of term loan (as a percent)						0.025
Warrant term						10 years
Number of options exercisable (in shares)						94,222
Fair value of exercisable options | $						$ 0.7
At-The-Market Offering
Class of Stock [Line Items]
Sale of stock, shares issued in transaction (in shares)				2,982,038	2,982,038
Consideration received on transaction | $				$ 28.6	$ 28.6
American Depositary Shares | Initial Public Offering
Class of Stock [Line Items]
Amount authorized | $	$ 150.0
Ordinary shares
Class of Stock [Line Items]
Exercise of share options (in shares)		128,869	431,855
Vested (in shares)		42,518
Shares issued related to vesting of restricted share units (in shares)		29,220	12,763
Settled (in shares)		13,298
Restricted share units issued in settlement (in shares)			70,638
Vested not issued (in shares)		8,902	57,875
Common stock, par value (in GBP per share) | £ / shares		£ 0.008	£ 0.008				£ 0.008	£ 0.008	£ 0.008	£ 0.008	£ 0.008	£ 0.001
Ordinary shares | 2022 And 2023
Class of Stock [Line Items]
Restricted share units issued in settlement (in shares)		38,122
Deferred shares
Class of Stock [Line Items]
Common stock, par value (in GBP per share) | £ / shares		£ 21,921.504	£ 21,921.504				£ 21,921.504	£ 21,921.504	£ 21,921.504	£ 21,921.504	£ 21,921.504