Pensions and Postretirement Benefits Other than Pensions - Components of Net Periodic Benefit Costs (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Amortization of actuarial loss	$ 10,932	$ 11,719
Other Postretirement Benefits - All Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	537	628
Interest cost	2,705	2,580
Amortization of prior service cost	(141)	(141)
Net periodic benefit cost	3,101	3,067
Pension Benefits - Domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2,403	2,759
Interest cost	10,617	10,050
Expected return on plan assets	(13,391)	(13,665)
Amortization of actuarial loss	9,576	9,879
Net periodic benefit cost	9,205	9,023
Pension Benefits - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	3
Interest cost	3,724	4,040
Expected return on plan assets	(2,991)	(3,165)
Amortization of actuarial loss	1,356	1,840
Net periodic benefit cost	$ 2,091	$ 2,718