Fair Value Measurements (Narrative) (Details) - USD ($)		3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 29, 2017	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Apr. 24, 2017	Apr. 23, 2017	Nov. 30, 2016
Derivatives And Fair Value [Line Items]
Remaining shares authorized for issuance		67,000,000		67,000,000		67,000,000	67,000,000	670,000,000
Derivative liability		$ 387,000		$ 387,000		$ 2,443,000
Common stock closing price		$ 0.78		$ 0.78		$ 4.40
Fair value of shares issued				$ 22,000
Change in fair value of derivative liabilities		$ 1,920,000	$ (35,000)	$ 2,034,000	$ 1,371,000
Common Stock Issuance Agreement [Member]
Derivatives And Fair Value [Line Items]
Future shares of common stock approved to be issued per agreement						28,684
Common Stock Issuance Agreement Amendment [Member]
Derivatives And Fair Value [Line Items]
Shares issued per agreements	28,684			28,684
Fair value of shares issued	$ 22,000
Dilutive Financing Derivative Liability [Member]
Derivatives And Fair Value [Line Items]
Derivative liability		358,000		$ 358,000		$ 126,000
Fair value of shares issued				22,000
Dilutive Financing Derivative Liability [Member] | Common Stock Issuance Agreement Amendment [Member]
Derivatives And Fair Value [Line Items]
Change in fair value of derivative liabilities		(104,000)		(104,000)
November 2016 Warrant Derivative Liability [Member]
Derivatives And Fair Value [Line Items]
Derivative liability		$ 358,000		$ 358,000		$ 2,043,000
Common stock closing price		$ 0.78		$ 0.78		$ 4.40
Number of securities called by warrants									533,500
June 2016 Offering Liability [Member]
Derivatives And Fair Value [Line Items]
Derivative liability		$ 29,000		$ 29,000		$ 274,000
Common stock closing price		$ 0.78		$ 0.78		$ 4.40
Number of securities called by warrants			106,383		106,383