Share-based payment arrangements - Stock options activity (Details) - 2018 Long Term Incentive Plan - $ / shares	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Number of options
Outstanding at Beginning	23,578,470	25,908,778
Forfeited during the year	(1,834,219)	(1,314,134)
Expired during the year	(821,945)	(123,666)
Exercised during the year	(1,269,953)	(5,849,945)
Granted during the year	4,713,315	4,957,437
Outstanding at Ending	24,365,668	23,578,470
Options exercisable at December 31	15,761,157	15,876,940
Weighted average exercise price
Outstanding at Beginning	$ 6.76	$ 4.14
Forfeited during the year	12.89	8.61
Expired during the year	3.28	7.52
Exercised during the year	0.41	1.37
Granted during the year	6.67	14.63
Outstanding at Ending	6.73	6.76
Options exercisable at December 31	$ 5.67	$ 4.48

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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Number of options outstanding, including both vested and non-vested options.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Number of share options (or share units) exercised during the current period.

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