Pensions and Postretirement Benefits Other than Pensions - Components of Net Periodic Benefit Costs (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Amortization of actuarial loss	$ (11,687)		$ (23,357)
Pension Benefits - Domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2,759	$ 2,440	5,518	$ 4,880
Interest cost	10,051	10,710	20,101	21,421
Expected return on plan assets	(13,665)	(13,136)	(27,330)	(26,271)
Amortization of actuarial loss	9,878	7,006	19,757	14,011
Net periodic benefit cost	9,023	7,020	18,046	14,041
Pension Benefits - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	3	5	6
Interest cost	3,972	5,009	7,902	9,935
Expected return on plan assets	(3,112)	(5,100)	(6,191)	(10,115)
Amortization of actuarial loss	1,809	2,158	3,600	4,280
Net periodic benefit cost	2,671	2,070	5,316	4,106
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	628	601	1,256	1,202
Interest cost	2,580	2,826	5,160	5,652
Amortization of prior service cost	(142)	(141)	(283)	(283)
Net periodic benefit cost	$ 3,066	$ 3,286	$ 6,133	$ 6,571