Summary of Company's Balance Sheet Related Pension and Other Postretirement Benefit Plan (Detail) - USD ($) $ in Thousands	Apr. 20, 2019	Dec. 29, 2018
Pension And Other Postretirement Benefit Expense [Abstract]
Current liability	$ 1,283	$ 1,283
Noncurrent liability	37,664	39,149
Accumulated other comprehensive loss, net of tax	$ 103,388	$ 105,036

Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as noncurrent.

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Period Type:	instant