Right of use of assets - Narrative (Details)	1 Months Ended				6 Months Ended
	Aug. 31, 2021 USD ($) ft²	Feb. 28, 2021 GBP (£)	Nov. 30, 2019 GBP (£)	May 31, 2019 ft²	Jun. 30, 2022 GBP (£)	Jun. 21, 2022	Jul. 31, 2021
Eastbourne Terrace, London, UK
Lessee, Lease, Description [Line Items]
Annual lease payment			£ 780,000
Refundable lease deposit			£ 130,000
Lease rental relief		£ 32,500
New York, NY
Lessee, Lease, Description [Line Items]
Net rentable area | ft²				200
Lease cancellation notification period (in days)				30 days
Soho, London, UK
Lessee, Lease, Description [Line Items]
Refundable lease deposit					£ 136,200
Lease term							2 years
Operating Leases, Noncancelable Term					24 months
Operating lease, monthly payment					£ 136,200
San Francisco, CA
Lessee, Lease, Description [Line Items]
Refundable lease deposit | $	$ 20,000
Net rentable area | ft²	2,526
Operating lease, monthly payment | $	$ 10,000
Advance rent upon lease execution | $	$ 9,000
Denmark Hill, London, UK
Lessee, Lease, Description [Line Items]
Lease term						5 years
Operating lease, annual payment					£ 180,000