Restructuring Costs (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restructuring Costs [Abstract]
Restructuring Reserve	$ 47		$ 1		$ 47	$ 1
Severance Costs					65
Defined Benefit Plan, Special termination Benefits cost					26
Restructuring Charges	$ 80	$ 11	$ 1	$ 1	$ 91	$ 2	$ 2