Reconciles the Denominators of the Company's Calculation for Basic and Diluted Net Income per Share (Detail) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jul. 03, 2020	Jun. 28, 2019	Jul. 03, 2020	Jun. 28, 2019
Schedule Of Earnings Per Share Basic and Diluted [Line Items]
Shares used in basic per share computation	52,259	52,745	52,417	52,641
Shares used in diluted per share computation	53,139	53,872	53,404	53,849
Employee Stock Option
Schedule Of Earnings Per Share Basic and Diluted [Line Items]
Effect of dilutive stock outstanding	340	470	360	463
Restricted Stock Units (RSUs)
Schedule Of Earnings Per Share Basic and Diluted [Line Items]
Effect of dilutive stock outstanding	540	657	627	745