Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income before income taxes (benefit):
Domestic	$ 3,540.4	$ 3,655.4	$ 3,386.7
Foreign	1,588.4	1,277.6	1,380.6
Income before income tax expense and equity in loss of investee, net of tax	5,128.8	4,933.0	4,767.3
Current
Federal	2,201.4	1,304.3	1,214.1
State	57.0	55.1	38.6
Foreign	108.6	52.9	54.5
Total	2,367.0	1,412.3	1,307.2
Deferred
Federal	241.0	(125.6)	(129.6)
State	9.9	(3.8)	(1.9)
Foreign	(159.2)	(45.6)	(14.1)
Total	91.7	(175.0)	(145.6)
Total income tax expense	$ 2,458.7	$ 1,237.3	$ 1,161.6