CONSOLIDATED INTERIM STATEMENTS OF COMPREHENSIVE (LOSS) INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net (loss) income	$ (9)	$ 66	$ 43	$ 139
Foreign exchange translation adjustment	(50)	(34)	(11)	25
Defined benefit pension plan adjustment, net of tax (Note 18)				1
Changes in fair value of effective cash flow hedges, net of tax (Note 14)	(2)	(1)	(2)	2
Total other comprehensive (loss) income, net of tax	(52)	(35)	(13)	28
Comprehensive (loss) income	$ (61)	$ 31	$ 30	$ 167

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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