Income Taxes - Income from Continuing Opearations Before Income Taxes and Tax Rate Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income from Continuing Operations Before Income Taxes
Domestic	$ 1,653	$ 1,660	$ 1,669
Foreign	1,255	1,059	1,030
Income from Continuing Operations Before Income Taxes	$ 2,908	$ 2,719	$ 2,699
Reconciliation Between the U.S. Federal Statutory Tax Rate and The Effective Tax Rate
U.S. federal statutory tax rate	35.00%	35.00%	35.00%
State income taxes, net of U.S. federal tax benefit	1.30%	1.40%	1.60%
Differences between U.S. federal statutory and foreign tax rates	(3.60%)	(3.10%)	(3.50%)
Nontaxable foreign interest income	(2.10%)	(3.30%)	(3.60%)
Tax effect of foreign dividends	1.50%	2.80%	2.10%
Tax relief for U.S. manufacturers	(1.40%)	(1.60%)	(1.50%)
Other, net	(0.70%)	(1.10%)	(0.10%)
Effective tax rate	30.00%	30.10%	30.00%