Leases Other supplemental information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Leases [Abstract]
Operating cash flows from operating leases	$ 316
Operating cash flows from finance leases	51
Financing cash flows from finance leases	24
Right-of-Use Assets Obtained in Exchange for Operating Lease Liability	1,362	[1]
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	$ 74
Operating Lease, Weighted Average Remaining Lease Term	9 years 6 months
Finance Lease, Weighted Average Remaining Lease Term	5 years 4 months 24 days
Operating Lease, Weighted Average Discount Rate, Percent	4.40%

[1] Primarily consists of operating lease right-of-use assets exchanged for lease obligations upon implementation of the new lease accounting standard on January 1, 2019.