Postretirement Benefit Plans - Fair Value Changes Within Asset Categories for which Fair Value Measurements Use Significant Unobservable Inputs Level 3 (Detail) - Insurance Contracts [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 2,241	$ 2,426
Sale proceeds (benefit payments)	(168)	(178)
Change in unrealized gain	11	135
Foreign exchange impact	(115)	(142)
Ending balance	$ 1,969	$ 2,241