Employee Benefit Plans - Summary of Components Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax [Abstract]
Net actuarial loss	$ 489	$ 77
Net prior service cost	9	9
Accumulated other comprehensive loss, net of tax	$ 498	$ 86