Supplemental Disclosure of Cash Flow Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Oct. 02, 2015	Sep. 30, 2016	Oct. 02, 2015
Cash paid during period:
Income taxes			$ 13,375	$ 17,087
Non-cash investing and financing activities:
Unrealized gain (loss) on short-term investments	$ (19)	$ 13	65	(4)
Vested stock unit awards issued to settle accrued bonuses			6,334	6,169
Accrual for capital expenditures			$ 739	$ 805