Business Optimization Initiatives (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Restructuring Cost and Reserve [Line Items]
Cash expenses	$ 12	$ 4	$ 28	$ 32
Non-cash expenses	2	1	4	1
Reserve adjustments		(37)	(29)	(37)
Total business optimization items	14	(32)	3	(4)
Discontinued operations				(8)
Business optimization items in continuing operations	$ 14	$ (32)	$ 3	$ (12)