Retirement Benefits (Components of Net Periodic Benefit Cost for Defined Benefit Plans and Other Postretirement Plans) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 254	$ 294
Interest cost	660	747
Expected return on plan assets	(944)	(1,175)
Net amortization	642	827
Net periodic benefit cost	612	693
Non-U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	482	299
Interest cost	308	350
Expected return on plan assets	(264)	(219)
Net amortization	382	238
Net periodic benefit cost	908	668
Other Postretirement Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	152	132
Interest cost	204	174
Net amortization	(198)	(154)
Net periodic benefit cost	$ 158	$ 152