Employee benefit plans - Restricted Stock Units Activity (Details) - $ / shares shares in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
RSUs [Member]
Shares (in thousands)
Non-vested shares at beginning of period (shares)	8,714
Granted (shares)	5,813
Vested (shares)	(4,644)
Forfeited (shares)	(1,156)
Non-vested shares at end of period (shares)	8,727	8,714
Weighted-average grant date fair value
Non-vested shares at beginning of period (in dollars per share)	$ 6.52
Weighted average price of shares granted (usd per share)	7.68	$ 8.83	$ 4.59
Weighted average price of shares vested (usd per share)	6.64
Weighted average price of shares forfeited (usd per share)	6.86
Non-vested shares at end of period (in dollars per share)	$ 7.19	$ 6.52
Performance Shares [Member]
Shares (in thousands)
Non-vested shares at beginning of period (shares)	1,134
Granted (shares)	604
Vested (shares)	(744)
Forfeited (shares)	(308)
Non-vested shares at end of period (shares)	686	1,134
Weighted-average grant date fair value
Non-vested shares at beginning of period (in dollars per share)	$ 6.68
Weighted average price of shares granted (usd per share)	8.70
Weighted average price of shares vested (usd per share)	6.45
Weighted average price of shares forfeited (usd per share)	8.46
Non-vested shares at end of period (in dollars per share)	$ 7.93	$ 6.68

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(3)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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-Publisher FASB
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-Topic 718
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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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- Definition

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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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ References

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-Publisher FASB
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