Restructuring (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013 Positions
Restructuring Plan, 2014 [Member]
Restructuring Cost and Reserve [Line Items]
Workforce reduction, positions	590
Restructuring charges paid	$ 9
Restructuring costs	86
Restructuring Plan, 2013 [Member]
Restructuring Cost and Reserve [Line Items]
Workforce reduction, positions		520
Restructuring charges paid	32	10
Restructuring costs	49	49
Restructuring Plan, 2012 [Member]
Restructuring Cost and Reserve [Line Items]
Reserve accrual adjustment	$ 7