Summary of Income Tax Benefit (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Summary of income tax provision (benefit)
Tax provision based on net income	$ 7,909	$ 2,571
Benefit of ASU 2016-09	(1,775)	(2,723)
Total income tax provision (benefit)	$ 6,134	$ (152)