Option Activity and Changes (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016
Shares
Options outstanding at January 2, 2016	2,433,647
Options granted	422,500
Options cancelled and forfeited	(107,230)
Options exercised	(8,553)
Options outstanding at December 31, 2016	2,740,364	2,433,647
Vested and expected to vest at December 31, 2016	2,624,994
Options exercisable at December 31, 2016	1,829,765
Weighted Average Exercise Price
Options outstanding at January 2, 2016	$ 7.52
Options granted	4.88
Options cancelled and forfeited	10.69
Options exercised	4.47
Options outstanding at December 31, 2016	7.00	$ 7.52
Vested and expected to vest at December 31, 2016	7.07
Options exercisable at December 31, 2016	$ 7.73
Weighted Average Remaining Contractual Term
Options outstanding	3 years 7 months 21 days	4 years 1 month 6 days
Vested and expected to vest at December 31, 2016	3 years 6 months 18 days
Options exercisable at December 31, 2016	2 years 8 months 27 days
Aggregate Intrinsic Value
Options outstanding at January 2, 2016	$ 141,546
Options outstanding at December 31, 2016	5,837,900	$ 141,546
Vested and expected to vest at December 31, 2016	5,476,403
Options exercisable at December 31, 2016	$ 3,082,215