Shareholders' Equity - Schedule of Shares Repurchase Plans (Details) - USD ($) $ / shares in Units, shares in Millions	12 Months Ended
	Dec. 31, 2016	Jul. 31, 2016	Mar. 31, 2015
Equity, Class of Treasury Stock [Line Items]
Shares Purchased	21.1
Average Cost per Share (USD per share)	$ 64.70
Total Purchased	$ 1,365,000,000
2015 Program
Equity, Class of Treasury Stock [Line Items]
Amount of common stock authorized for repurchase			$ 1,800,000,000.00
Shares Purchased	12.1
Average Cost per Share (USD per share)	$ 58.83
Total Purchased	$ 715,000,000
2016 Program
Equity, Class of Treasury Stock [Line Items]
Amount of common stock authorized for repurchase		$ 1,400,000,000.0
Shares Purchased	9.0
Average Cost per Share (USD per share)	$ 72.66
Total Purchased	$ 650,000,000