Stockholders' Equity - Summary of Stockholders' Equity Transactions (Detail) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 29, 2013	Jun. 30, 2012	Jun. 29, 2013	Jun. 30, 2012	Dec. 31, 2012
Beginning balance			$ 10,292,000
Issuance of common stock net of offering cost			1,945,000	6,621,000
Issuance of common stock net of offering cost, Shares	4,751,284		4,751,284		4,193,690
Conversion of preferred stock to common stock, Value
Stock-based compensation, Value			295,000
Net loss	(2,436,000)	(3,419,000)	(4,844,000)	(6,407,000)	10,900,000
Ending balance	7,689,000		7,689,000		10,292,000
Convertible Preferred Stock [Member]
Beginning balance			1,000
Beginning balance, Shares			564,642
Conversion of preferred stock to common stock, Shares			(28,122)
Conversion of preferred stock to common stock, Value
Ending balance	1,000		1,000
Ending balance, Shares	536,520		536,520
Common Stock [Member]
Beginning balance			4,000
Beginning balance, Shares			4,193,690
Issuance of common stock net of offering cost			1,000
Issuance of common stock net of offering cost, Shares	513,827		513,827
Conversion of preferred stock to common stock, Shares			23,432
Conversion of preferred stock to common stock, Value
Cancellation of shares from reverse stock split			(2,865)
Stock-based compensation, Shares			23,200
Ending balance	5,000		5,000
Ending balance, Shares	4,751,284		4,751,284
Capital in Excess of Par Value [Member]
Beginning balance			272,231,000
Issuance of common stock net of offering cost			1,945,000
Conversion of preferred stock to common stock, Value
Stock-based compensation, Value			295,000
Ending balance	274,471,000		274,471,000
Accumulated Deficit [Member]
Beginning balance			(261,944,000)
Conversion of preferred stock to common stock, Value
Net loss			(4,844,000)
Ending balance	$ (266,788,000)		$ (266,788,000)