Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ 1,214	$ 1,363	$ 2,664	$ 2,388
Unrecognized tax benefits	5,800		5,800		$ 5,700
Expected change in unrecognized tax benefits	4,200		4,200
Decrease in unrecognized tax benefits in next twelve months	$ 2,000		$ 2,000