SUPPLEMENTAL CONSOLIDATED FINANCIAL STATEMENT INFORMATION – Impact of Adoption of Topic 606 on Condensed Consolidated Statements of Operations and Comprehensive Loss (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	May 01, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Common stock dividend declared, percentage of shares outstanding	5.00%
Operating revenues		$ 40,448	$ 45,108	$ 126,486	$ 119,114
Operating costs:
Operating expenses		34,419	36,238	104,393	109,010
Loss from operations		(5,234)	(4,299)	(13,165)	(31,942)
Net loss		$ (5,171)	$ (2,922)	$ (12,591)	$ (27,002)
Basic and diluted loss per share of common stock			$ (0.13)		$ (1.19)
Weighted average equivalent common shares outstanding - assuming dilution		22,926,764	22,786,745	22,901,558	22,765,548
ASU 2014-09 | As Previously Reported
Operating revenues			$ 45,627		$ 118,023
Operating costs:
Operating expenses			36,594		107,639
Loss from operations			(4,136)		(31,662)
Net loss			$ (2,759)		$ (26,722)
Basic and diluted loss per share of common stock			$ (0.13)		$ (1.23)
Weighted average equivalent common shares outstanding - assuming dilution			21,701,662		21,681,474
ASU 2014-09 | Adjustments
Operating revenues			$ (519)		$ 1,091
Operating costs:
Operating expenses			(356)		1,371
Loss from operations			(163)		(280)
Net loss			$ (163)		$ (280)
Stock Dividend Adjustments
Operating costs:
Basic and diluted loss per share of common stock					$ 0.04
Weighted average equivalent common shares outstanding - assuming dilution			1,085,083		1,084,074