Weighted Average Shares Outstanding (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Excluded common stock equivalents			21.5
Weighted average shares outstanding
Weighted average shares outstanding - basic	1,370.1	1,357.6	1,341.2
Net effect of common stock equivalents	22.6	19.6	0.0
Weighted average shares outstanding - assuming dilution	1,392.7	1,377.2	1,341.2