Basis of preparation and significant accounting policies (Details) - Credit cards	12 Months Ended
Dec. 31, 2020
Bottom of range
Disclosure of expected impact of initial application of new standards or interpretations [line items]
Expected credit loss	2 years
Top of range
Disclosure of expected impact of initial application of new standards or interpretations [line items]
Expected credit loss	6 years

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

No definition available.

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