Earnings Per Share and Equity - Schedule of Earnings per Share (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share [Abstract]
Net income attributable to common shareholders	$ 539	$ 95	$ 1,125	$ 1,086
Weighted average common shares outstanding — basic	967	934	967	931
Assumed exercise and/or distributions of stock-based awards	2	2	1	1
Weighted average common shares outstanding — diluted	969	936	968	932