Divestitures and Pension Termination (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Jan. 31, 2011	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Divestitures and Assets Held for Sale [Abstract]
Purchase price for divestiture of business/controlling interest	$ 1,500
Proceeds from business divestitures, net of costs				$ 0	$ 12	$ 30	$ 10	$ 1,450
Pension termination charges		$ 36	$ 0	$ 44	$ 0