Pension and Other Postretirement Benefits - Components of Actuarial (Gains) Losses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Change from RPI to CPI		$ (8,760)
Pension Benefits [Member] | U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Changes in assumptions	$ (16,642)	12,566
GMP equalization	0	0
Change from RPI to CPI	0	0
Other	(420)	1,259
Total actuarial (gains) losses	(17,062)	13,825
Pension Benefits [Member] | Foreign Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Changes in assumptions	(5,298)	616
GMP equalization	982	0
Change from RPI to CPI	0	(8,760)
Other	(1,446)	190
Total actuarial (gains) losses	(5,762)	(7,954)
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Changes in assumptions	(914)	(1,103)
GMP equalization	0	0
Change from RPI to CPI	0	0
Other	(229)	(1,067)
Total actuarial (gains) losses	$ (1,143)	$ (2,170)