Computation of EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net income available to common shareholders	$ 599	$ 492	$ 1,667	$ 1,434
Weighted average number of common shares (in shares)	812,521	764,435	802,694	737,141
Effect of dilutive outstanding equity-based awards (in shares)	10,585	9,588	9,713	9,681
Weighted average number of diluted common shares (in shares)	823,106	774,023	812,407	746,822
Basic EPS (in dollars per share)	$ 0.74	$ 0.64	$ 2.08	$ 1.95
Diluted EPS (in dollars per share)	$ 0.73	$ 0.64	$ 2.05	$ 1.92
Anti-dilutive awards (in shares)	5,416	7,492	6,088	9,210