Equity Equity (Schedule of Share Repurchases) (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017
Class of Stock [Line Items]
Payments for Repurchase of Common Stock			$ 237	$ 733
Class A [Member]
Class of Stock [Line Items]
Treasury Stock, Shares, Acquired	1.0	2.8	3.1	11.8
Payments for Repurchase of Common Stock	$ 73	$ 182	$ 237	$ 758
Under share repurchase program \| Class A [Member]
Class of Stock [Line Items]
Treasury Stock, Shares, Acquired	0.8	2.6	2.3	11.2
Payments for Repurchase of Common Stock	$ 60	$ 167	$ 180	$ 717
To fund certain obligations under equity compensation plans \| Class A [Member]
Class of Stock [Line Items]
Treasury Stock, Shares, Acquired	0.2	0.2	0.8	0.6
Payments for Repurchase of Common Stock	$ 13	$ 15	$ 57	$ 41