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. 30, 2019	Mar. 31, 2018
Retirement Benefits [Abstract]
Service cost	$ 126	$ 150
Interest cost	347	317
Expected return on plan assets	(411)	(446)
Amortization of actuarial losses	221	186
Net periodic pension cost	$ 283	$ 207