Leases (Lease and Other Information) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Operating Lease, Cost	$ 59	$ 45	$ 106	$ 90
Short-term Lease, Cost	14	12	27	24
Sublease Income	(4)	(4)	(7)	(8)
Lease, Cost	69	53	126	106
Operating Lease, Payments	46	44	90	89
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 33	$ 0	$ 356	$ 0
Operating Lease, Weighted Average Remaining Lease Term	7 years	7 years	7 years	7 years
Weighted Average Discount Rate, Percent	3.45%	3.90%	3.45%	3.90%
Other Noncurrent Assets [Member]
Operating Lease, Right-of-Use Asset	$ 917		$ 917		$ 575
Other Current Liabilities [Member]
Operating Lease, Liability, Current	193		193		158
Other Noncurrent Liabilities [Member]
Operating Lease, Liability, Noncurrent	$ 815		$ 815		$ 482