Employer Sponsored Benefit Plan (Defined Benefit Pension Plan with an Accumulated Benefit Obligation In Excess of Plan Assets) (Detail) - Domestic Pension Plan - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 50,086	$ 48,081
Accumulated benefit obligation	50,086	48,081
Fair value of plan assets	$ 37,038	$ 35,413