Retirement Plans - Components of Net Periodic Benefit Cost (Detail) - Domestic Retirement Plans - 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]
Service cost	$ 32	$ 40	$ 65	$ 75
Interest cost	464	482	929	965
Recognized net actuarial loss	401	202	802	406
Net periodic benefit cost	$ 897	$ 724	$ 1,796	$ 1,446