Weighted Average Actuarial Assumptions to Determine Benefit Obligations (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.10%	1.90%
Rate of compensation increase	3.30%	3.50%
Health care cost trend rate:
Net periodic benefit cost rate of compensation increase	3.30%	3.50%	3.50%
Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.80%	4.40%
Expected return on plan assets	8.50%	8.50%	8.50%
Rate of compensation increase	2.60%	2.80%
Health care cost trend rate:
Assumed for next year	6.20%	6.40%
Ultimate rate	4.90%	4.50%
Year that the ultimate rate is reached	2047	2047
Net periodic benefit cost rate of compensation increase	2.80%	3.10%	3.00%