Leases Expense (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Leases [Abstract]
Operating lease expense	$ 50	$ 156
Variable lease expense	$ 4	14
Cash paid for operating leases, operating cash flows		155
Operating lease right-of-use asset additions		$ 172