Income Taxes - Income from Continuing Opearations Before Income Taxes and Tax Rate Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income from Continuing Operations Before Income Taxes
Domestic	$ 1,774	$ 1,806	$ 1,653
Foreign	1,620	1,464	1,255
Income Before Taxes	$ 3,394	$ 3,270	$ 2,908
Reconciliation Between the U.S. Federal Statutory Tax Rate and The Effective Tax Rate
U.S. federal statutory tax rate	21.00%	35.00%	35.00%
U.S. tax effect of foreign earnings	1.50%	0.50%	0.70%
Tax effect of U.S. federal tax law change	(0.10%)	20.10%	0.00%
State income taxes, net of U.S. federal tax benefit	1.60%	1.20%	1.30%
Differences between U.S. federal statutory and foreign tax rates	2.10%	(3.50%)	(3.60%)
Nontaxable foreign interest income	(1.70%)	(1.70%)	(2.10%)
Tax effect of foreign dividends	1.00%	0.40%	0.80%
Tax relief for U.S. manufacturers	(0.00%)	(1.40%)	(1.40%)
Excess tax benefits from stock-based compensation	(0.30%)	(1.50%)	(0.00%)
Other, net	(0.60%)	(0.70%)	(0.70%)
Effective tax rate	24.50%	48.40%	30.00%