Share-based compensation (Details) shares in Millions	3 Months Ended
Mar. 31, 2020 shares
Stock Options
Stock issued or granted during period [Abstract]
Stock options granted (in shares)	0.4
Award vesting period	3 years
Restricted Stock Units
Stock issued or granted during period [Abstract]
Restricted stock units granted (in shares)	0.5
Award vesting period	3 years
Tranche One \| Stock Options
Stock issued or granted during period [Abstract]
Award vesting rights, percentage	33.33%
Tranche One \| Restricted Stock Units
Stock issued or granted during period [Abstract]
Award vesting rights, percentage	33.33%
Tranche Two \| Stock Options
Stock issued or granted during period [Abstract]
Award vesting rights, percentage	33.33%
Tranche Two \| Restricted Stock Units
Stock issued or granted during period [Abstract]
Award vesting rights, percentage	33.33%
Tranche Three \| Stock Options
Stock issued or granted during period [Abstract]
Award vesting rights, percentage	33.33%
Tranche Three \| Restricted Stock Units
Stock issued or granted during period [Abstract]
Award vesting rights, percentage	33.33%

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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 (a)(1)
-URI http://asc.fasb.org/extlink&oid=116856206&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

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)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

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- Definition

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

+ 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
-Subparagraph (c)(1)(iv)(1)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

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- Definition

Percentage of vesting of award under share-based payment arrangement.

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