Assets and Liabilities Measured at Fair Value (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Dec. 31, 2016	Oct. 01, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	$ 55	$ 85
Total	619	292
Fair value of borrowings	20,986	21,079
Interest rate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset	16	132
Derivative Liabilities	(149)	(13)
Foreign exchange
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset	1,025	596
Derivative Liabilities	(339)	(510)
Other Derivative
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset	12	6
Derivative Liabilities	(1)	(4)
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	55	85
Total	55	85
Fair value of borrowings	0	0
Level 1 | Interest rate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset	0	0
Derivative Liabilities	0	0
Level 1 | Foreign exchange
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset	0	0
Derivative Liabilities	0	0
Level 1 | Other Derivative
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset	0	0
Derivative Liabilities	0	0
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0	0
Total	564	207
Fair value of borrowings	19,597	19,500
Level 2 | Interest rate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset	16	132
Derivative Liabilities	(149)	(13)
Level 2 | Foreign exchange
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset	1,025	596
Derivative Liabilities	(339)	(510)
Level 2 | Other Derivative
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset	12	6
Derivative Liabilities	(1)	(4)
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	0	0
Total	0	0
Fair value of borrowings	1,389	1,579
Level 3 | Interest rate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset	0	0
Derivative Liabilities	0	0
Level 3 | Foreign exchange
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset	0	0
Derivative Liabilities	0	0
Level 3 | Other Derivative
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset	0	0
Derivative Liabilities	$ 0	$ 0