Consolidated Statements of Shareholders' Equity (Parenthetical) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Statement of Stockholders' Equity [Abstract]
Treasury shares (shares)	45,992,714	38,634,545
Foreign currency translation, tax	$ 2	$ 2
Amortization of prior service cost and unrecognized gains and (losses) included in total benefit cost, tax	8	8
(Increase)/Decrease in net actuarial losses, tax	1	1
Reclassification adjustment for amounts recognized in income, tax	0	1
Deferred derivative gains (losses), tax	$ 0	$ (2)
Cash dividends declared (dollars per share)	$ 0.16	$ 0.14

Aggregate dividends declared during the period for each share of common stock outstanding.

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Amount of tax expense (benefit), before 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 of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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Amount of tax expense (benefit), before reclassification adjustments, related to 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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Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

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