Income Taxes Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Amount
Income before income taxes		$ 5,646	$ 4,958	$ 5,079
Federal statutory tax		1,976	1,735	1,778
State tax effect, net of federal benefit		22	27	29
Foreign tax effect		(188)	(144)	(108)
Impact of foreign tax credits 1	[1]	(141)	(281)	(183)
Impact of settlements with tax authorities		0	(147)	0
Other, net		(82)	(40)	(54)
Income tax expense		$ 1,587	$ 1,150	$ 1,462
Percent
Federal statutory tax		35.00%	35.00%	35.00%
State tax effect, net of federal benefit		0.40%	0.50%	0.60%
Foreign tax effect		(3.30%)	(2.90%)	(2.10%)
Impact of foreign tax credits 1	[1]	(2.50%)	(5.70%)	(3.60%)
Impact of settlements with tax authorities		0.00%	(2.90%)	0.00%
Other, net		(1.50%)	(0.80%)	(1.10%)
Income tax expense		28.10%	23.20%	28.80%
Repatriation benefits of current year foreign earnings		$ (116)	$ (172)	$ (177)
Other foreign tax credit benefits		$ 25	$ 109	$ 6

[1] Included within the impact of foreign tax credits were repatriation benefits of current year foreign earnings of $116 million, $172 million and $177 million, in addition to other foreign tax credit benefits which become eligible in the United States of $25 million, $109 million and $6 million for 2016, 2015 and 2014, respectively.