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Employee Benefit Plans - Components of Net Periodic Pension Cost for Defined Benefit Pension Plan and Retirement Plan (Detail) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2018
Apr. 01, 2017
Retirement Benefits [Abstract]    
Service cost $ 150 $ 133
Interest cost 317 332
Expected return on plan assets (446) (383)
Amortization of actuarial losses 186 203
Net periodic pension cost $ 207 $ 285