Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock Outstanding [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings Including Treasury Stock [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 31, 2018	22,266,000
Balance at Dec. 31, 2018	$ 22	$ 378,855	$ (122,325)	$ (112,363)	$ (2,324)	$ 141,865
Net income	0	0	0	(1,103)	0	(1,103)
Change in accumulated other comprehensive income	$ 0	0	0	0	1,550	1,550
Issuance of treasury stock upon exercise of stock options, stock appreciation rights and vesting of restricted stock units by employees and directors (in shares)	531,000
Issuance of treasury stock upon exercise of stock options, stock appreciation rights and vesting of restricted stock units by employees and directors	$ 1	44	5,319	(4,121)	0	1,243
Equity-based compensation	$ 0	5,838	0	0	0	5,838
Issuance of treasury stock upon purchase of common stock under employee stock purchase plan (in shares)	206,000
Issuance of treasury stock upon purchase of common stock under employee stock purchase plan		0	2,066	(87)	0	$ 1,979
Purchase of treasury stock (in shares)						0
Balance (in shares) at Sep. 30, 2019	23,003,000
Balance at Sep. 30, 2019	$ 23	384,737	(114,940)	(117,674)	(774)	$ 151,372
Balance (in shares) at Jun. 30, 2019	22,803,000
Balance at Jun. 30, 2019	$ 23	382,849	(116,940)	(117,297)	(946)	147,689
Net income	0	0	0	484	0	484
Change in accumulated other comprehensive income	$ 0	0	0	0	172	172
Issuance of treasury stock upon purchase of common stock under employee stock purchase plan (in shares)	104,000
Issuance of treasury stock upon purchase of common stock under employee stock purchase plan		0	1,043	(35)	0	1,008
Issuance of treasury stock upon exercise of stock options, stock appreciation rights and vesting of restricted stock units by employees and directors (in shares)	96,000
Issuance of treasury stock upon exercise of stock options, stock appreciation rights and vesting of restricted stock units by employees and directors		15	957	(826)	0	146
Equity-based compensation	$ 0	1,873	0	0	0	1,873
Balance (in shares) at Sep. 30, 2019	23,003,000
Balance at Sep. 30, 2019	$ 23	384,737	(114,940)	(117,674)	(774)	151,372
Balance (in shares) at Dec. 31, 2019	23,111,000
Balance at Dec. 31, 2019	$ 23	386,534	(113,862)	(118,712)	(889)	153,094
Net income	0	0	0	(5,434)	0	(5,434)
Change in accumulated other comprehensive income	$ 0	0	0	0	201	201
Issuance of treasury stock upon exercise of stock options, stock appreciation rights and vesting of restricted stock units by employees and directors (in shares)	578,000
Issuance of treasury stock upon exercise of stock options, stock appreciation rights and vesting of restricted stock units by employees and directors	$ 1	88	5,812	(4,424)	0	1,477
Equity-based compensation	$ 0	6,546	0	0	0	6,546
Issuance of treasury stock upon purchase of common stock under employee stock purchase plan (in shares)	211,000
Issuance of treasury stock upon purchase of common stock under employee stock purchase plan		0	2,116	(49)	0	$ 2,067
Purchase of treasury stock (in shares)	(305,000)					304,704
Purchase of treasury stock		0	(3,736)	0	0	$ (3,736)
Balance (in shares) at Sep. 30, 2020	23,595,000
Balance at Sep. 30, 2020	$ 24	393,168	(109,670)	(128,619)	(688)	154,215
Balance (in shares) at Jun. 30, 2020	23,410,000
Balance at Jun. 30, 2020	$ 23	390,734	(111,532)	(125,909)	(554)	152,762
Net income	0	0	0	(1,891)	0	(1,891)
Change in accumulated other comprehensive income	$ 0	0	0	0	(134)	(134)
Issuance of treasury stock upon purchase of common stock under employee stock purchase plan (in shares)	106,000
Issuance of treasury stock upon purchase of common stock under employee stock purchase plan		1	1,063	(20)	0	1,044
Issuance of treasury stock upon exercise of stock options, stock appreciation rights and vesting of restricted stock units by employees and directors (in shares)	79,000
Issuance of treasury stock upon exercise of stock options, stock appreciation rights and vesting of restricted stock units by employees and directors	$ 1	0	799	(799)	0	1
Equity-based compensation	$ 0	2,433	0	0	0	2,433
Balance (in shares) at Sep. 30, 2020	23,595,000
Balance at Sep. 30, 2020	$ 24	$ 393,168	$ (109,670)	$ (128,619)	$ (688)	$ 154,215