Share capital - Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Disclosure of share capital, reserves and other equity interest [Abstract]
Net income from continuing operations	$ 308,859	$ 134,767
Non-controlling interests	(22,459)	(16,183)
Net income from continuing operations (attributable to shareholders of the Company)	286,400	118,584
Dilutive impact of gain on fair value of convertible notes	0	(10,651)
Diluted net income from continuing operations (attributable to shareholders of the Company)	286,400	107,933
Net income (attributable to shareholders of the Company)	293,382	28,938
Diluted net income (attributable to shareholders of the Company)	$ 293,382	$ 18,287
Basic weighted average number of shares outstanding (in shares)	1,014,100	986,755
Effect of dilutive convertible notes (in shares)	0	49,393
Effect of dilutive securities, stock options (in shares)	8,021	10,762
Effect of dilutive securities, restricted share units (in shares)	794	458
Diluted weighted average number of shares outstanding (in shares)	1,022,915	1,047,368
Earnings per share from continuing operations, basic (in USD per share)	$ 0.28	$ 0.12
Earnings per share from continuing operations, diluted (in USD per share)	0.28	0.10
Earnings per share (attributable to Shareholders of the Company), Basic (in USD per share)	0.29	0.03
Earnings per share (attributable to Shareholders of the Company), Diluted (in USD per share)	$ 0.29	$ 0.02

Adjustment To Profit (Loss) For Gain On Fair Value Of Convertible Notes

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Dilutive Effect Of Restricted Stock Units On Number Of Ordinary Shares

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Disclosure of share capital, reserves and other equity interest [Abstract]

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The weighted average number of ordinary shares outstanding plus the weighted average number of ordinary shares that would be issued on the conversion of all the dilutive potential ordinary shares into ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

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The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator) divided by the weighted average number of ordinary shares outstanding during the period (the denominator).

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Basic earnings (loss) per share from continuing operations. [Refer: Basic earnings (loss) per share; Continuing operations [member]]

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The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator), divided by the weighted average number of ordinary shares outstanding during the period (the denominator), both adjusted for the effects of all dilutive potential ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

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Diluted earnings (loss) per share from continuing operations. [Refer: Continuing operations [member]; Diluted earnings (loss) per share]

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The number of dilutive potential ordinary shares that relate to the assumed conversion of the entity's convertible instruments.

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The number of dilutive potential ordinary shares that relate to the assumed exercise of the entity's share options.

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The profit (loss) from continuing and discontinued operations attributable to non-controlling interests. [Refer: Profit (loss); Non-controlling interests]

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The profit (loss) attributable to ordinary equity holders of the parent entity, adjusted for the effects of all dilutive potential ordinary shares. [Refer: Profit (loss)]

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The profit (loss) from continuing and discontinued operations attributable to owners of the parent. [Refer: Profit (loss)]

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The profit (loss) from continuing operations. [Refer: Continuing operations [member]; Profit (loss)]

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The profit (loss) from continuing operations attributable to ordinary equity holders of the parent entity. [Refer: Continuing operations [member]; Profit (loss) from continuing operations]

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The profit (loss) from continuing operations attributable to ordinary equity holders of the parent entity, adjusted for the effects of all dilutive potential ordinary shares. [Refer: Profit (loss) from continuing operations]

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The number of ordinary shares outstanding at the beginning of the period, adjusted by the number of ordinary shares bought back or issued during the period multiplied by a time-weighting factor.

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