Earnings Per Share (EPS) And Dividends (Dividend Payments On Common Stock) (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended
Apr. 30, 2018	Mar. 31, 2018	Mar. 31, 2017
DIVIDENDS PAID PER SHARE OF COMMON STOCK (in dollars per share)		$ 0.45	$ 0.43
Dividend Payments on Common Stock		$ 227	$ 218
Subsequent Event [Member]
Common Stock, Dividends, Per Share, Declared	$ 0.45

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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

+ References

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Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585

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