Restructuring of Operations - Restructuring Charges and Related Payments and Adjustments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 2	$ 5
Restructuring Reserve [Roll Forward]
Beginning balance	40
Charges to restructuring	3
Adjustments of accruals	(1)
Discontinued operations charges	1
Cash payments	(10)
Ending Balance	33
Total Restructuring Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3	6
Employee Termination Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges		4
Restructuring Reserve [Roll Forward]
Beginning balance	27
Charges to restructuring	1
Adjustments of accruals	(1)
Discontinued operations charges
Cash payments	(6)
Ending Balance	21
Exit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges		2
Restructuring Reserve [Roll Forward]
Beginning balance	13
Charges to restructuring	2
Discontinued operations charges	1
Cash payments	(4)
Ending Balance	$ 12