Other Expenses (Restructuring Charges) (Details) (Other Expenses [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period	$ 23	$ 21	$ 46	$ 23
Restructuring charges	22	16	53	65
Cash payments	(24)	(17)	(78)	(68)
Balance, end of period	21	20	21	20
Total restructuring charges incurred since inception of initiative	328	224	328	224
Severance [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period	16	12	40	23
Restructuring charges	20	14	46	51
Cash payments	(22)	(13)	(72)	(61)
Balance, end of period	14	13	14	13
Total restructuring charges incurred since inception of initiative	287	192	287	192
Lease and Asset Impairment [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period	7	9	6	0
Restructuring charges	2	2	7	14
Cash payments	(2)	(4)	(6)	(7)
Balance, end of period	7	7	7	7
Total restructuring charges incurred since inception of initiative	$ 41	$ 32	$ 41	$ 32