Leases (Lease and Other Information) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Operating Lease, Cost	$ 198
Short-term Lease, Cost	46
Sublease Income	16
Lease, Cost	228
Operating Lease, Payments	176
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 112
Operating Lease, Weighted Average Remaining Lease Term	6 years
Operating Lease, Weighted Average Discount Rate, Percent	4.09%
Other Noncurrent Assets [Member]
Operating Lease, Right-of-Use Asset	$ 575
Other Current Liabilities [Member]
Operating Lease, Liability, Current	158
Other Noncurrent Liabilities [Member]
Operating Lease, Liability, Noncurrent	$ 482