Pension and Other Postretirement Benefits - Assumptions Regarding Net Periodic Pension and Other Postretirement Benefit Costs (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Pension Plan [Member] | U.S. Defined Benefit Pension Plans [Member] | U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected long-term rate of return			8.00%
Wages increases	3.00%	3.00%	4.00%
Defined Benefit Pension Plan [Member] | Foreign Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate			3.50%
Expected long-term rate of return	4.45%	5.40%	5.40%
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate			4.00%
Minimum [Member] | Defined Benefit Pension Plan [Member] | U.S. Defined Benefit Pension Plans [Member] | U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.02%	4.20%	4.00%
Expected long-term rate of return	6.95%	6.90%
Minimum [Member] | Defined Benefit Pension Plan [Member] | Foreign Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.50%	3.00%
Minimum [Member] | Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.90%	3.80%
Maximum [Member] | Defined Benefit Pension Plan [Member] | U.S. Defined Benefit Pension Plans [Member] | U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.25%	4.40%	4.10%
Expected long-term rate of return	7.50%	7.75%
Maximum [Member] | Defined Benefit Pension Plan [Member] | Foreign Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.65%	3.65%
Maximum [Member] | Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.13%	4.20%