Stockbased Compensation, Stock Option Disclosures (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected Stock Price Volatility		20.00%	21.00%	24.00%
Risk Free Interest Rate		1.90%	1.20%	1.40%
Expected Life of Options (years)		4 years 4 months	4 years 4 months	4 years 4 months
Expected Annual Dividend		0.40%	0.50%	0.50%
Weighted Average Grant Date Fair Value of Options Granted in Period (in dollars per share)		$ 30.73	$ 24.54	$ 27.04
Total Intrinsic Value of Options Exercised in Period		$ 199	$ 176	$ 181
Options Outstanding [Roll Forward]
Options Outstanding, Beginning Balance		8.8
Granted		2.6
Issued in connection with an acquisition		0.3
Exercised		(2.2)
Canceled / Expired		(0.5)
Options Outstanding, Ending Balance		9.0	8.8
Options, Additional Disclosures [Abstract]
Options Outstanding, Weighted Average Exercise Price, Beginning of Period (in dollars per share)		$ 98.69
Grants in Period, Weighted Average Exercise Price (in dollars per share)		167.59
Issued in Connection with an Acquisition in Period, Weighted Average Exercise Price		114.06
Exercises in Period, Weighted Average Exercise Price (in dollars per share)		79.16
Canceled / Expired in Period, Weighted Average Exercise Price (in dollars per share)		134.56
Options Outstanding, Weighted Average Exercise Price, End of Period (in dollars per share)		$ 121.78	$ 98.69
Options Outstanding, Weighted Average Remaining Contractual Term		4 years 2 months
Options Vested and Unvested Expected to Vest		8.5
Options Vested and Unvested Expected to Vest, Weighted Average Exercise Price (in dollars per share)		$ 119.92
Options Vested and Unvested Expected to Vest, Weighted Average Remaining Contractual Term		4 years 1 month
Options Vested and Unvested Expected to Vest, Aggregate Intrinsic Value	[1]	$ 597
Options Exercisable		4.1
Options Exercisable, Weighted Average Exercise Price (in dollars per share)		$ 90.31
Options Exercisable, Weighted Average Remaining Contractual Term		2 years 7 months
Options Exercisable, Intrinsic Value	[1]	$ 413
Common Stock, Market Value Per Share		$ 189.88
Minimum [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award Requisite Service Period		3 years
Option Term		7 years
Maximum [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award Requisite Service Period		5 years
Option Term		10 years

[1] Market price per share on December 31, 2017 was $189.88. The intrinsic value is zero for options with exercise prices above the market price.