Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Supplemental Cash Flow Information [Abstract]
Cash Paid For Interest	$ 790	$ 687	$ 533
Cash Paid For Income Taxes	896	591	479
Non-cash Investing and Financing Activities [Abstract]
Declared but unpaid dividends	77	69	61
Issuance of stock upon vesting of restricted stock units	182	170	125
Cash and cash equivalents	2,399	2,103
Restricted Cash Included in Other Current Assets	21	12
Restricted Cash Included in Other Assets	2	2
Cash, Cash Equivalents and Restricted Cash	$ 2,422	$ 2,117	$ 1,361	$ 811
Restricted Cash and Cash Equivalents, Current, Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssetsCurrent
Restricted Cash and Cash Equivalents, Noncurrent, Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssetsNoncurrent