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 | ||