Dividends Declared (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Declaration Date	Nov. 29, 2017	Sep. 19, 2017	Nov. 30, 2016	Sep. 20, 2016
Dividend Per Share	$ 0.42	$ 0.42	$ 0.39	$ 0.39	$ 0.84	$ 0.78
Record Date	Feb. 15, 2018	Nov. 16, 2017	Feb. 16, 2017	Nov. 17, 2016
Total Amount	$ 3,236	$ 3,238	$ 3,012	$ 3,024
Payment Date	Mar. 08, 2018	Dec. 14, 2017	Mar. 09, 2017	Dec. 08, 2016

Aggregate dividends declared 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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Date the declared dividend will be paid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

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Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

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Date the dividend to be paid was declared, in CCYY-MM-DD format.

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Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

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