Weighted Average Actuarial Assumptions to Determine Net Period Cost (Detail) - United States Pension Plan of US Entity [Member]	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.70%	4.10%	4.90%
Expected return on plan assets	8.50%	8.50%	8.50%
Rate of compensation increase	3.10%	3.00%	3.00%
Health care cost trend rate	6.60%	6.70%	7.20%