Equity (Common Stock - Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Nov. 01, 2018	May 01, 2018	Nov. 01, 2017	Nov. 10, 2016
Business Acquisition [Line Items]
Common Stock, Shares, Issued	1,171,824,242	1,168,710,101
Cost of shares issued	$ 89	$ 167	$ 195
Stock Repurchase Program, Authorized Amount				$ 2,000	$ 1,500	$ 2,000	$ 3,000
Class of Stock Disclosures [Abstract]
Repurchase amount outstanding	$ 1,300
Repurchase Shares	88,029,138	56,599,540	6,948,739
Treasury Stock, Value, Acquired, Cost Method	$ 3,992	$ 2,927	$ 372
Common Shares Issued For Stock Options [Member]
Business Acquisition [Line Items]
Common stock, shares issued	3,114,141	4,680,116	4,439,219
Cost of shares issued	$ 108	$ 158	$ 166
Treasury Shares Issued For Stock Options [Member]
Business Acquisition [Line Items]
Issued Treasury Stock	0	0	0