Employee Benefit Plans - Summary of Actuarial Assumptions Used to Determine Net Periodic Benefit Cost (Credit) (Detail) - Defined Benefit Pension Plans	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
U.S.
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Discount rate	3.90%	4.10%	3.80%
Long-term return on plan assets	7.50%	7.50%	7.50%
Foreign
Pension Plans Postretirement And Other Employee Benefits [Line Items]
Discount rate	2.10%	2.60%	2.50%
Increase in future compensation levels	2.60%	2.90%	2.60%
Long-term return on plan assets	2.50%	3.90%	4.60%