Shareholders' Equity Schedule of Shares Issued and Treasury Stock (Details) - Issued [Member] - shares shares in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Issued and Treasury Shares [Line Items]
Stock Issued During Period, Shares, New Issues		10	200
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(993)	(983)	(779)
Equity Awards Granted, Vested and Exercised	9		4
Ending Balance	(1,002)	(993)	(983)