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	Convertible Preferred Stock - Series C [Member]
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					(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		$ (1,638)				(3,710)	$ (2,072)
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
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		$ (958)			(1,629)	$ (1,629)	(671)
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
Beginning balance at Dec. 31, 2018	$ 1	$ 30		241,988	(210,771)	31,248
Beginning balance (in shares) at Dec. 31, 2018	9,968	29,943,086
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	$ 0		323	0	323
Conversion of convertible preferred stock into common stock	$ 0	$ 1		(1)	0	0
Conversion of convertible preferred stock into common stock (in shares)	(3,090)	1,148,698
Exercise of stock options	$ 0	$ 0		0	0	0
Exercise of stock options (in shares)	0	28,824
Net loss					(1,333)	(1,333)
Ending balance at Mar. 31, 2019	$ 1	$ 31		242,310	(212,104)	30,238
Ending balance (in shares) at Mar. 31, 2019	6,878	31,120,608
Beginning balance at Dec. 31, 2018	$ 1	$ 30		241,988	(210,771)	31,248
Beginning balance (in shares) at Dec. 31, 2018	9,968	29,943,086
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss		$ (2,226)				(2,415)	(189)
Ending balance at Jun. 30, 2019	$ 1	$ 33		242,611	(213,186)	29,459
Ending balance (in shares) at Jun. 30, 2019	2,103	32,903,287
Beginning balance at Mar. 31, 2019	$ 1	$ 31		242,310	(212,104)	30,238
Beginning balance (in shares) at Mar. 31, 2019	6,878	31,120,608
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	$ 0		303	0	303
Conversion of convertible preferred stock into common stock	$ 0	$ 2		(2)	0	0
Conversion of convertible preferred stock into common stock (in shares)	(4,775)	1,775,093
Exercise of stock options	$ 0	$ 0		0	0	0
Exercise of stock options (in shares)	0	7,586
Net loss		$ (1,007)			(1,082)	(1,082)	$ (75)
Ending balance at Jun. 30, 2019	$ 1	$ 33		$ 242,611	$ (213,186)	$ 29,459
Ending balance (in shares) at Jun. 30, 2019	2,103	32,903,287