Capital Transactions (Details 2) - USD ($) $ / shares in Units, $ in Millions							3 Months Ended		9 Months Ended
	May. 29, 2015	May. 13, 2015	Feb. 03, 2015	May. 30, 2014	May. 14, 2014	Feb. 06, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Dividends
Dividends per common share (in dollars per share)			$ 0.23			$ 0.20	$ 0	$ 0	$ 0.23	$ 0.20
Dividends paid		$ 167			$ 143				$ 170	$ 147
Dividend equivalent payment	$ 3			$ 4