Income Taxes (Unaudited) (Details 1) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Jun. 30, 2018
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income Tax Expense (Benefit)	$ 140	$ 167	$ 528	$ 500
Effective income tax rate	17.80%	21.70%	22.30%	23.00%
Effective Income Tax Rate Reconciliation, Tax Settlement, Amount		$ (42)	$ (42)	$ (42)
Effective Income Tax Rate Reconciliation, Tax Credit, Research, Amount	$ 45		55
Effective Income Tax Rate Reconciliation, Deduction, Qualified Production Activity, Amount	35		32
Income Tax Contingency [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible	$ 110		$ 110
Maximum | Scenario, Forecast [Member]
Income Tax Contingency [Line Items]
Tax Adjustments, Settlements, and Unusual Provisions					$ (30)