Restructuring Costs (Restructuring Activities) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Restructuring Reserve [Roll Forward]
Liability at beginning of period	$ 124	$ 170
Amounts Accrued	10	22
Cash Paid	(34)	(65)
Other	(2)	(3)
Liability at end of period	98	124
Severance [Member]
Restructuring Reserve [Roll Forward]
Liability at beginning of period	11	36
Amounts Accrued	4	9
Cash Paid	(7)	(33)
Other	(1)	(1)
Liability at end of period	7	11
Future Rent Under Non-Cancelable Leases and Other Costs [Member]
Restructuring Reserve [Roll Forward]
Liability at beginning of period	113	134
Amounts Accrued	6	13
Cash Paid	(27)	(32)
Other	(1)	(2)
Liability at end of period	91	113
Corporate Segment [Member]
Restructuring Reserve [Roll Forward]
Amounts Accrued	$ 10