Pensions and Postretirement Benefits Other than Pensions - Components of Net Periodic Benefit Costs (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost - employer	$ 393	$ 487
Interest cost	2,472	2,313
Amortization of prior service cost	(102)	(135)
Net periodic benefit cost	2,763	2,665
United States | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost - employer	2,244	2,580
Interest cost	9,875	9,210
Expected return on plan assets	(11,990)	(13,498)
Amortization of actuarial loss	8,284	8,235
Net periodic benefit cost	8,413	6,527
International | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost - employer	0	0
Interest cost	2,821	2,906
Expected return on plan assets	(2,947)	(3,155)
Amortization of actuarial loss	949	1,110
Net periodic benefit cost	$ 823	$ 861