Fair Value of Financial Assets and Liabilities - Derivative Instruments (Change in Fair Value of Series B Convertible Stock) (Details)	3 Months Ended
	Mar. 31, 2016 USD ($)
Derivatives And Fair Value [Line Items]
Balance, Warrant Liability	$ 6,000
Balance, Series B Redeemable Preferred Stock Liability	1,493,000
Balance, Warrant Liability	2,000
Balance, Series B Redeemable Preferred Stock Liability	91,000
Series B redeemable convertible preferred stock [Member]
Derivatives And Fair Value [Line Items]
Balance, Series B Redeemable Preferred Stock Liability	1,493,000
Changes in estimated fair value	(1,402,000)
Balance, Series B Redeemable Preferred Stock Liability	91,000
Warrant Liability [Member]
Derivatives And Fair Value [Line Items]
Balance, Warrant Liability	6,000
Changes in estimated fair value	(4,000)
Balance, Warrant Liability	$ 2,000