Leases - Supplemental Balance Sheet Information Related to Leases (Details) $ in Millions	Sep. 30, 2020 USD ($)
Other Assets
Lessee, Lease, Description [Line Items]
Right-of-use assets recorded in Other Assets	$ 418
Accrued Expenses
Lessee, Lease, Description [Line Items]
Current lease liabilities recorded in Payables, accrued expenses and other current liabilities	106
Deferred Income Taxes and Other Liabilities
Lessee, Lease, Description [Line Items]
Non-current lease liabilities recorded in Deferred Income Taxes and Other Liabilities	$ 336