Shareholders' Equity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Shares Repurchased During Period	10
Shares Repurchased, Average Cost Per Share	$ 112.30
Common share repurchases	$ 1,130	$ 3,024
Share Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	61
Cash Dividend Annual Rate Per Share			$ 2.00	$ 1.50