Summary Of Defined Benefit Pension Plans' Assets Fair Value (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 527	$ 553	$ 517
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Total assets	12	6
US Stock
Defined Benefit Plan Disclosure [Line Items]
Total assets	126	113
Non US Stock
Defined Benefit Plan Disclosure [Line Items]
Total assets	129	163
Non US Government Securities
Defined Benefit Plan Disclosure [Line Items]
Total assets	103	91
Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Total assets	133	167
Other Assets
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 24	$ 13