New Accounting Standards (Statement of Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Expenses Excluding Interest
Compensation and benefits	$ 737	$ 662	$ 2,252	$ 2,026
Taxes on income	296	327	780	940
Net income	923	$ 618	2,572	$ 1,757	[1]
Balances Without Adoption of ASC 606 [Member] | ASU 2014-09 [Member]
Expenses Excluding Interest
Compensation and benefits	744		2,279
Taxes on income	294		773
Net income	918		2,552
Effect of Change Higher/(Lower) [Member] | ASU 2014-09 [Member]
Expenses Excluding Interest
Compensation and benefits	(7)		(27)
Taxes on income	2		7
Net income	$ 5		$ 20

[1] Adjusted for the retrospective adoption of ASU 2016-18. See Note 2.