CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Preferred Stock [Member] Convertible Preferred Stock - Series C [Member]	Common Stock [Member]	Common Stock Issuable [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Total
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative accounting adjustment from adoption of new standard net of tax | ASU 2014-09 [Member]	$ 0	$ 0	$ 0	$ 0	$ (234)	$ (234)
Cumulative accounting adjustment from adoption of new standard net of tax | ASU 2017-11 [Member]	0	0	0	2,614	(2,547)	67
Beginning balance at Dec. 31, 2017	$ 4	$ 4	$ 0	223,829	(203,957)	19,880
Beginning balance (in shares) at Dec. 31, 2017	36,182	4,304,425	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	$ 0	$ 0	19	0	19
Conversion of convertible preferred stock into common stock	$ 0	$ 0	$ 0	0	0	0
Conversion of convertible preferred stock into common stock (in shares)	(202)	75,000	0
Net loss	$ 0	$ 0	$ 0	0	(2,081)	(2,081)
Ending balance at Mar. 31, 2018	$ 4	$ 4	$ 0	226,462	(208,819)	17,651
Ending balance (in shares) at Mar. 31, 2018	35,980	4,379,425	0
Beginning balance at Dec. 31, 2017	$ 4	$ 4	$ 0	223,829	(203,957)	19,880
Beginning balance (in shares) at Dec. 31, 2017	36,182	4,304,425	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss						(4,318)
Ending balance at Sep. 30, 2018	$ 1	$ 30	$ 0	241,654	(211,056)	30,629
Ending balance (in shares) at Sep. 30, 2018	9,968	29,943,086	0
Beginning balance at Mar. 31, 2018	$ 4	$ 4	$ 0	226,462	(208,819)	17,651
Beginning balance (in shares) at Mar. 31, 2018	35,980	4,379,425	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	$ 0	$ 0	184	0	184
Conversion of convertible preferred stock into common stock	$ (3)	$ 10	$ 0	(7)	0	0
Conversion of convertible preferred stock into common stock (in shares)	(25,865)	9,615,332	0
Sale of common stock, net of expenses	$ 0	$ 16	$ 0	14,648	0	14,664
Sale of common stock, net of expenses (in shares)	0	15,740,741	0
Common stock issuable	$ 0		$ 0	0	0	$ 0
Common stock issuable (in shares)		0	153,004			0
Net loss	0	$ 0	$ 0	0	(1,629)	$ (1,629)
Ending balance at Jun. 30, 2018	$ 1	$ 30	$ 0	241,287	(210,448)	30,870
Ending balance (in shares) at Jun. 30, 2018	10,115	29,735,498	153,004
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	$ 0	$ 0	367	0	367
Conversion of convertible preferred stock into common stock	$ 0	$ 0	$ 0	0	0	0
Conversion of convertible preferred stock into common stock (in shares)	(147)	54,584	0
Sale of common stock, net of expenses	$ 0	$ 0	$ 0	0	0	0
Sale of common stock, net of expenses (in shares)	0	153,004	(153,004)
Common stock issuable	$ 0		$ 0	0	0	$ 0
Common stock issuable (in shares)		0	0			0
Net loss	0	$ 0	$ 0	0	(608)	$ (608)
Ending balance at Sep. 30, 2018	$ 1	$ 30	$ 0	241,654	(211,056)	30,629
Ending balance (in shares) at Sep. 30, 2018	9,968	29,943,086	0
Beginning balance at Dec. 31, 2018	$ 1	$ 30	$ 0	241,988	(210,771)	31,248
Beginning balance (in shares) at Dec. 31, 2018	9,968	29,943,086	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	$ 0	$ 0	323	0	323
Conversion of convertible preferred stock into common stock	$ 0	$ 1	$ 0	(1)	0	0
Conversion of convertible preferred stock into common stock (in shares)	(3,090)	1,148,698	0
Exercise of stock options	$ 0	$ 0	$ 0	0	0	0
Exercise of stock options (in shares)	0	28,824	0
Net loss	$ 0	$ 0	$ 0	0	(1,333)	(1,333)
Ending balance at Mar. 31, 2019	$ 1	$ 31	$ 0	242,310	(212,104)	30,238
Ending balance (in shares) at Mar. 31, 2019	6,878	31,120,608	0
Beginning balance at Dec. 31, 2018	$ 1	$ 30	$ 0	241,988	(210,771)	31,248
Beginning balance (in shares) at Dec. 31, 2018	9,968	29,943,086	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss						(3,275)
Ending balance at Sep. 30, 2019	$ 1	$ 33	$ 0	242,868	(214,046)	28,856
Ending balance (in shares) at Sep. 30, 2019	2,103	32,903,287	0
Beginning balance at Mar. 31, 2019	$ 1	$ 31	$ 0	242,310	(212,104)	30,238
Beginning balance (in shares) at Mar. 31, 2019	6,878	31,120,608	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	$ 0	$ 0	303	0	303
Conversion of convertible preferred stock into common stock	$ 0	$ 2	$ 0	(2)	0	0
Conversion of convertible preferred stock into common stock (in shares)	(4,775)	1,775,093	0
Exercise of stock options	$ 0	$ 0	$ 0	0	0	0
Exercise of stock options (in shares)	0	7,586	0
Net loss	$ 0	$ 0	$ 0	0	(1,082)	(1,082)
Ending balance at Jun. 30, 2019	$ 1	$ 33	$ 0	242,611	(213,186)	29,459
Ending balance (in shares) at Jun. 30, 2019	2,103	32,903,287	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	$ 0	$ 0	257	0	257
Net loss	0	0	0	0	(860)	(860)
Ending balance at Sep. 30, 2019	$ 1	$ 33	$ 0	$ 242,868	$ (214,046)	$ 28,856
Ending balance (in shares) at Sep. 30, 2019	2,103	32,903,287	0