Summary of Significant Accounting Policies (Basic and Diluted EPS Calculation for Continuing Operations) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net income before non-controlling interests	$ 396	$ 306	$ 344	$ 727	$ 159	$ 279	$ 536	$ 696	$ 1,773	$ 1,670	$ 1,510
Less: Net income attributable to non-controlling interests									31	20	20
Net income attributable to the Company									$ 1,742	$ 1,650	$ 1,490
Basic weighted average common shares outstanding (in shares)									506	506	513
Dilutive effect of potentially issuable common shares (in shares)									5	5	6
Diluted weighted average common shares outstanding (in shares)									511	511	519
Average stock price used to calculate common stock equivalents (in dollars per share)									$ 97.23	$ 83.13	$ 77.30