Employee Benefit Plans - Components of Net Periodic Pension Cost for Defined Benefit Pension Plan and Retirement Plan (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Retirement Benefits [Abstract]
Service cost	$ 133	$ 133	$ 398	$ 399
Interest cost	332	341	997	1,025
Expected return on plan assets	(382)	(370)	(1,147)	(1,111)
Amortization of actuarial losses	202	191	607	572
Net periodic pension cost	$ 285	$ 295	$ 855	$ 885