CONSOLIDATED AND COMBINED INTERIM STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 38	$ 929	$ 177	$ 1,137
Foreign exchange translation adjustment	102	(3)	127	(251)
Defined benefit pension plan adjustment, net of tax (Note 15)			1
Changes in fair value of effective cash flow hedges, net of tax (Note 14)	8	5	10	24
Changes in currency basis reserve		(3)		(3)
Total other comprehensive (loss) income, net of tax	110	(1)	138	(230)
Comprehensive income (loss)	$ 148	$ 928	$ 315	$ 907

Other comprehensive income loss changes in currency basis reserve.

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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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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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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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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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