Profit Sharing, Retirement Savings Plans and Defined Benefit Pension Plans - Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
U.S.
Net periodic benefit cost
Discount rate	4.00%	4.30%	3.90%
Expected long-term rate of return	6.70%	6.70%	6.50%
Rate of compensation increase		3.00%	3.00%
International
Net periodic benefit cost
Discount rate	2.40%	2.80%	3.00%
Expected long-term rate of return	5.00%	4.30%	4.70%
Rate of compensation increase	2.40%	2.50%	2.40%