CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	(Accumulated Deficit)	Total
Balance at Dec. 31, 2016	$ 224	$ 100,485	$ (19)	$ (41,686)	$ 59,004
Balance (in shares) at Dec. 31, 2016	22,371,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect on adoption of ASC 2016-09 (see Note 2)				4,758	4,758
Exercise of common stock options		13			13
Exercise of common stock (in shares)	4,000
Issuance of unrestricted stock	$ 1	(1)
Issuance of unrestricted stock (in shares)	143,000
Shares surrendered by employees to pay taxes related to unrestricted stock		(186)			(186)
Shares surrendered by employees to pay taxes related to unrestricted stock (in shares)	(33,000)
Issuance of common stock under employee stock purchase plan		61			61
Issuance of common stock under employee stock purchase plan (in shares)	13,000
Stock-based compensation expense		663			663
Repurchase of common stock	$ (10)	(4,789)			(4,799)
Repurchase of common stock (in shares)	(1,005,000)
Accumulated other comprehensive loss:
Unrealized gain on securities			28		28
Deferred tax expense on unrealized gain			$ (9)		(9)
Net income				1,001	1,001
Balance at Dec. 31, 2017	$ 215	96,246		(35,927)	$ 60,534
Balance (in shares) at Dec. 31, 2017	21,493,000				21,493,440
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of unrestricted stock	$ 1	(1)
Issuance of unrestricted stock (in shares)	136,000
Shares surrendered by employees to pay taxes related to unrestricted stock		(107)			$ (107)
Shares surrendered by employees to pay taxes related to unrestricted stock (in shares)	(25,000)
Issuance of common stock under employee stock purchase plan		50			50
Issuance of common stock under employee stock purchase plan (in shares)	14,000
Stock-based compensation expense		580			580
Repurchase of common stock	$ (1)	(392)			(393)
Repurchase of common stock (in shares)	(102,000)
Accumulated other comprehensive loss:
Net income				1,233	1,233
Balance at Dec. 31, 2018	$ 215	$ 96,376		$ (34,694)	$ 61,897
Balance (in shares) at Dec. 31, 2018	21,516,000				21,515,872