Basis of Presentation - Cumulative Effect of Changes in Consolidated Financial Statements (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018	Dec. 31, 2017
ASSETS
Other current assets	$ 755		$ 1,068	$ 998
Other assets	744		756	397
LIABILITIES AND STOCKHOLDERS' DEFICIT
Other current liabilities	4,762		5,487	5,529
Other long-term liabilities	300		215	268
Accumulated deficit	(190,219)		(184,990)	(185,324)
CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS:
Revenues	11,335	$ 7,601
Selling, general and administrative expenses	6,851	3,480
Net loss	(5,229)	$ (3,129)
Effect of Change Higher/(Lower)
ASSETS
Other current assets	72
Other assets	359
LIABILITIES AND STOCKHOLDERS' DEFICIT
Other current liabilities	129
Other long-term liabilities	53
Accumulated deficit	334
CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS:
Revenues	(87)
Selling, general and administrative expenses	2
Net loss	(85)
Accounting Standards Update 2014-09 | Balances Without Adoption of ASC 606
ASSETS
Other current assets	683
Other assets	385
LIABILITIES AND STOCKHOLDERS' DEFICIT
Other current liabilities	4,633
Other long-term liabilities	247
Accumulated deficit	(189,885)
CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS:
Revenues	11,422
Selling, general and administrative expenses	6,849
Net loss	$ (5,144)
Balance at December 31, 2017
ASSETS
Other current assets				998
Other assets				397
LIABILITIES AND STOCKHOLDERS' DEFICIT
Other current liabilities				5,529
Other long-term liabilities				268
Accumulated deficit				$ (185,324)
Adjustments due to ASC 606 | Accounting Standards Update 2014-09
ASSETS
Other current assets			70
Other assets			359
LIABILITIES AND STOCKHOLDERS' DEFICIT
Other current liabilities			(42)
Other long-term liabilities			(53)
Accumulated deficit			$ (334)