Pensions and Postretirement Benefits Other than Pensions - Components of Net Periodic Benefit Costs (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Document Fiscal Year Focus	2017
Service cost			$ 11,771	$ 13,559
Amortization of prior service credit	$ 141	$ 141
Net periodic benefit cost			$ 64,842	$ 58,384
Pension Benefits - Domestic
Defined Benefit Plan Disclosure [Line Items]
Service cost	2,465	2,403
Interest cost	9,813	10,617
Expected return on plan assets	(13,515)	(13,391)
Amortization of actuarial loss	9,281	9,576
Net periodic benefit cost	8,044	9,205
Pension Benefits - International
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	2
Interest cost	2,770	3,724
Expected return on plan assets	(2,707)	(2,991)
Amortization of actuarial loss	1,310	1,356
Net periodic benefit cost	1,373	2,091
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	501	537
Interest cost	2,515	2,705
Amortization of prior service credit	(141)	(141)
Net periodic benefit cost	$ 2,875	$ 3,101