Pension and Other Postretirement Benefits - Net Periodic Pension and Other Postretirement Benefit Costs (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Defined Benefit Pension Plan [Member] | U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 60	$ 37	$ 182	$ 167
Interest cost	1,337	1,776	4,012	5,381
Expected return on plan assets	(3,248)	(3,232)	(9,746)	(9,621)
Amortization of prior service cost	6	10	17	31
Amortization of actuarial (gain) loss	658	455	1,974	1,570
Net benefit (income) expense	(1,187)	(954)	(3,561)	(2,472)
Defined Benefit Pension Plan [Member] | Foreign Defined Benefits Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	111	127	285	332
Interest cost	207	265	626	781
Expected return on plan assets	(485)	(496)	(1,461)	(1,465)
Amortization of prior service cost	(77)	(72)	(231)	(212)
Amortization of actuarial (gain) loss	162	177	489	522
Net benefit (income) expense	(82)	1	(292)	(42)
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	61	56	183	169
Interest cost	45	71	136	211
Amortization of prior service cost	(258)	(255)	(773)	(763)
Amortization of actuarial (gain) loss	(19)	(34)	(58)	(104)
Net benefit (income) expense	$ (171)	$ (162)	$ (512)	$ (487)