Related party disclosures - Summary of Options Granted to Managing Director and Supervisory Directors (Detail)	12 Months Ended
Dec. 31, 2020 shares $ / shares
Performance Based Options [Member] \| Harpreet Singh
Disclosure of transactions between related parties [line items]
Description of Transactions with related party	Harpreet Singh
Type of option	Performance-based options
Grant date	June 30, 2020
Number of Options \| shares	1,598,000
Strike Price in USD \| $ / shares	$ 10
Expiration date	Jun. 30, 2030
Service Options [Member] \| Harpreet Singh
Disclosure of transactions between related parties [line items]
Description of Transactions with related party	Harpreet Singh
Type of option	Service options
Grant date	June 30, 2020
Number of Options \| shares	168,000
Strike Price in USD \| $ / shares	$ 10
Expiration date	Jun. 30, 2030
Service Options [Member] \| Peter Chambre
Disclosure of transactions between related parties [line items]
Description of Transactions with related party	Peter Chambré
Type of option	Service options
Grant date	June 30, 2020
Number of Options \| shares	25,000
Strike Price in USD \| $ / shares	$ 10
Expiration date	Jun. 30, 2030
Service Options [Member] \| Adam Stone
Disclosure of transactions between related parties [line items]
Description of Transactions with related party	Adam Stone
Type of option	Service options
Grant date	June 30, 2020
Number of Options \| shares	25,000
Strike Price in USD \| $ / shares	$ 10
Expiration date	Jun. 30, 2030
Service Options [Member] \| Christoph Hettich
Disclosure of transactions between related parties [line items]
Description of Transactions with related party	Christoph Hettich
Type of option	Service options
Grant date	June 30, 2020
Number of Options \| shares	25,000
Strike Price in USD \| $ / shares	$ 10
Expiration date	Jun. 30, 2030
Service Options [Member] \| Heather I. Mason
Disclosure of transactions between related parties [line items]
Description of Transactions with related party	Heather L. Mason
Type of option	Service options
Grant date	June 30, 2020
Number of Options \| shares	25,000
Strike Price in USD \| $ / shares	$ 10
Expiration date	Jun. 30, 2030
Service Options [Member] \| Michael G. Atieh
Disclosure of transactions between related parties [line items]
Description of Transactions with related party	Michael G. Atieh
Type of option	Service options
Grant date	June 30, 2020
Number of Options \| shares	25,000
Strike Price in USD \| $ / shares	$ 10
Expiration date	Jun. 30, 2030
Service Options [Member] \| Paul Carter
Disclosure of transactions between related parties [line items]
Description of Transactions with related party	Paul Carter
Type of option	Service options
Grant date	June 30, 2020
Number of Options \| shares	25,000
Strike Price in USD \| $ / shares	$ 10
Expiration date	Jun. 30, 2030
Service Options [Member] \| Eliot Forster
Disclosure of transactions between related parties [line items]
Description of Transactions with related party	Eliot Forster
Type of option	Service options
Grant date	September 14, 2020
Number of Options \| shares	25,000
Strike Price in USD \| $ / shares	$ 9.16
Expiration date	Sep. 13, 2030
Service Options One [Member] \| Harpreet Singh
Disclosure of transactions between related parties [line items]
Description of Transactions with related party	Harpreet Singh
Type of option	Service options
Grant date	December 17, 2020
Number of Options \| shares	168,000
Strike Price in USD \| $ / shares	$ 9.70
Expiration date	Dec. 17, 2030
Matching Stock Options [Member] \| Harpreet Singh
Disclosure of transactions between related parties [line items]
Description of Transactions with related party	Harpreet Singh
Type of option	Matching Stock options
Grant date	June 30, 2020
Number of Options \| shares	264,624
Strike Price in USD \| $ / shares	$ 10
Expiration date	Jun. 30, 2030
Matching Stock Options [Member] \| Peter Chambre
Disclosure of transactions between related parties [line items]
Description of Transactions with related party	Peter Chambré
Type of option	Matching Stock options
Grant date	June 30, 2020
Number of Options \| shares	211,974
Strike Price in USD \| $ / shares	$ 10
Expiration date	Jun. 30, 2030
Converted Options [Member] \| Harpreet Singh
Disclosure of transactions between related parties [line items]
Description of Transactions with related party	Harpreet Singh
Type of option	Converted options
Grant date	June 30, 2020
Number of Options \| shares	30,939
Strike Price in USD \| $ / shares	$ 1.06
Expiration date	Jul. 01, 2027
Converted Options One [Member] \| Harpreet Singh
Disclosure of transactions between related parties [line items]
Description of Transactions with related party	Harpreet Singh
Type of option	Converted options
Grant date	June 30, 2020
Number of Options \| shares	145,371
Strike Price in USD \| $ / shares	$ 1.17
Expiration date	Jan. 01, 2028

The date on which share-based payment arrangements are granted. [Refer: Share-based payment arrangements [member]]

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The description of related party transactions. [Refer: Related parties [member]]

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The exercise price of share options granted.

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