Summary Of Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 6	$ 5	$ 4
Interest cost	19	19	21
Expected return on plan assets	(33)	(30)	(27)
Defined Benefit Plan Amortization Of Unrecognized Amounts	7	8	5
Net periodic benefit cost	(1)	2	3
Employee Benefit Plans [Abstract]
Defined Benefit Plan, Benefit Obligation	722	779	720
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	32	(15)
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)	(24)	44
Defined Benefit Plan, Plan Assets, Amount	549	614	$ 523
Actual return on plan assets	(29)	59
Employer contributions	11	24
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss)	(21)	$ 32
Operating Expense [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	4
Selling, General and Administrative Expenses [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2