Summary Of Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Defined Benefit Plan, Benefit Obligation	$ 720	$ 656	$ 716
Employee Benefit Plans [Abstract]
Service cost	4	5	5
Interest cost	21	22	29
Expected return on plan assets	(27)	(31)	(32)
Defined Benefit Plan Amortization Of Unrecognized Amounts	5	5	3
Net periodic benefit cost	3	1	5
Defined Benefit Plan, Actuarial Gain (Loss)	(115)	32
Defined Benefit Plan, Foreign Currency Exchange Rate Gain (Loss)	(53)	(30)
Defined Benefit Plan, Benefits Paid	23	25
Defined Benefit Plan, Fair Value of Plan Assets	523	527	$ 553
Actual return on plan assets	60	5
Employer contributions	12	14
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Plan Assets	$ (53)	$ (20)