Earnings Per Share and Equity - Schedule of Earnings per Share (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Net income attributable to common shareholders	$ 824	$ 490	$ 1,899	$ 930
Weighted average common shares outstanding — basic	962	925	941	924
Assumed exercise and/or distributions of stock-based awards	3	2	2	2
Weighted average common shares outstanding — diluted	965	927	943	926