Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Summary of valuation of the Company's investments and financial instruments that are measured at fair value on a recurring basis

The following table summarizes the valuation of the Company’s financial instruments that are measured at fair value on a recurring basis: 

	December 31, 2015								December 31, 2014
	Fair value measurement category								Fair value measurement category
(In thousands)	Total		Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3
Liabilities:
Warrant liabilities	$	757	$	—	$	757	$	—	$	1,081	$	—	$	1,061	$	20

Summary of change in estimated fair values of warrant liabilities

The following table summarizes the change in the estimated fair value of the Company’s warrant liabilities: 

Warrant Liabilities (In thousands)
Balance at December 31, 2013	$	2,019
Warrant exercises	(965		)
Increase in fair value	27
Balance at December 31, 2014	1,081
Decrease in fair value	(324		)
Balance at December 31, 2015	$	757

Schedule of reconciliation of beginning and ending balances for the Company's fair value measurements using Level 3 inputs

A reconciliation of beginning and ending balances for the Company’s fair value measurements using Level 3 inputs is as follows:

	Year Ended December 31,
(In thousands)	2015			2014
Beginning balance	$	20		$	85
Decrease in fair value	(20		)	(65		)
Ending balance	$	—		$	20