Stockholders' Equity - Issuance of Common Stock and Warrants (Details) - USD ($)		1 Months Ended		6 Months Ended
	Mar. 21, 2016	Mar. 31, 2016	Nov. 30, 2013	Jul. 03, 2016	Jun. 28, 2015	Jan. 03, 2016	Jul. 31, 2013
Class of Stock [Line Items]
Offerings							$ 40,000,000.0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001	$ 0.001	$ 0.001		$ 0.001
Underwritten public offering price (in dollars per share)	$ 1.00	$ 1.00	$ 2.90	$ 0.94
Net proceeds	$ 8,800,000	$ 8,800,000	$ 23,100,000	$ 10,344,000	$ 409,000
Offering expenses		$ 1,200,000	$ 2,200,000	$ 1,197,000	$ 0
Warrants outstanding (in shares)				2,300,000
November 2009 financing
Class of Stock [Line Items]
Warrants expired (in shares)				1,900,000
Strike price of warrants (in dollars per share)				$ 2.15
June 2012 financing
Class of Stock [Line Items]
Warrants outstanding (in shares)				2,300,000
Strike price of warrants (in dollars per share)				$ 2.98
Common stock
Class of Stock [Line Items]
Aggregate shares of common stock issued	10,000,000.0	10,000,000	8,740,000