Condensed Consolidated Statement of Financial Position (Parenthetical) - $ / shares |
Mar. 31, 2016 |
Sep. 30, 2015 |
|---|---|---|
| Statement of Financial Position [Abstract] | ||
| Common stock, par value | $ 0.01 | $ 0.01 |
| Common stock, shares authorized | 1,000,000,000 | 1,000,000,000 |
| Common stock, shares issued | 143,800,000 | 183,800,000 |
| Common stock, shares held in treasury | 13,400,000 | 51,900,000 |