Pensions and Postretirement Benefits Other than Pensions - Details of Activity in Investment in European Infrastructure and Property Funds (Detail) - Significant Unobservable Inputs Level (3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 27,062	$ 25,812
Transfer into level 3	9,489	0
Disbursements	0	0
Change in fair value	3,545	2,798
Foreign currency translation effect	(6,300)	(1,548)
Ending balance	$ 33,796	$ 27,062