Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 03, 2020	Mar. 29, 2019
Cash paid during period:
Income taxes	$ 1,231	$ 440
Non-cash investing and financing activities:
Unrealized gain on investments	168	154
Vested stock unit awards issued to settle accrued bonuses	8,645	7,947
Accrual for capital expenditures	$ 229	1,903
Right-of-use asset obtained in exchange for operating lease obligations		$ 25,653