Pension and Other Postretirement Benefits - Components of Actuarial Losses (Gains) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Pension Benefits [Member] | U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Changes in assumptions	$ 27,380	$ (16,642)
GMP equalization	0	0
Other	295	(420)
Total actuarial losses (gains)	27,675	(17,062)
Pension Benefits [Member] | Foreign Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Changes in assumptions	6,277	(5,298)
GMP equalization	0	982
Other	831	(1,446)
Total actuarial losses (gains)	7,108	(5,762)
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Changes in assumptions	1,116	(914)
GMP equalization	0	0
Other	134	(229)
Total actuarial losses (gains)	$ 1,250	$ (1,143)