Stock-Based Compensation Expense - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 28, 2014 group	Sep. 29, 2013	Sep. 28, 2014 group	Sep. 29, 2013	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Groups within the employee population	2		2
Percentage of stock options granted to senior management	72.00%		72.00%
Percentage of stock options granted to all other employees	70.00%		70.00%
Estimated annual forfeiture rate	11.00%		11.00%
Estimated annual forfeiture rate for unvested options	12.00%		12.00%
Increase (decrease) to compensation expense	$ 288,000	$ 300,000
Weighted-average grant-date fair values, in dollars per share	$ 15.45	$ 8.07	$ 15.35	$ 8.07
Total intrinsic value	14,461,000	14,422,000	29,104,000	28,374,000
Total fair values of stock options vest	268,000	197,000	11,251,000	9,428,000
Unrecognized compensation expense	15,716,000		15,716,000
weighted average period to be recognized			1 year 4 months 6 days
Recognized Period Costs Capitalized Amount	$ 0		$ 0		$ 0
Stock Option And Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for stock option plans			4 years
Expiration period from grant day			10 years
General Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for stock option plans			4 years
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant under stock option plans	9,901,489		9,901,489
Expiration period from grant day			10 years
2015 Through Expected Life of Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield			0.56%