Pensions and Postretirement Benefits Other than Pensions - Components of Net Periodic Benefit Costs (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Plan amendment	$ 2,582
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	360	$ 393
Interest cost	1,830	2,472
Amortization of actuarial (gain) loss	(106)	(102)
Amortization of prior service cost (credit)	(22)	0
Net periodic benefit cost	2,062	2,763
United States | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	2,497	2,244
Interest cost	8,308	9,875
Expected return on plan assets	(14,194)	(11,990)
Amortization of actuarial (gain) loss	7,221	8,284
Amortization of prior service cost (credit)	192	0
Net periodic benefit cost	4,024	8,413
International | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	2,099	2,821
Expected return on plan assets	(2,218)	(2,947)
Amortization of actuarial (gain) loss	1,034	949
Amortization of prior service cost (credit)	66	0
Net periodic benefit cost	$ 981	$ 823