Restructuring of Operations - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	0 Months Ended	12 Months Ended
	Dec. 31, 2014 employee	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 21	$ 24	$ 47
Discontinued operations charges			1	3
Estimated reduction of employees over the next two years	200
Completion date period	2 years
Employee Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges		15	14	27
Discontinued operations charges
Exit Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges		6	10	20
Discontinued operations charges			$ 1	$ 3