Statements of Changes in Stockholders' Equity - USD ($)	Common Stock Outstanding [Member]		Additional Paid-in Capital [Member]	Treasury Stock [Member]	AOCI Attributable to Parent [Member]	Retained Earnings Including Treasury Stock [Member]	Total
Balance (in shares) at Dec. 31, 2016	21,932,000
Balance at Dec. 31, 2016	$ 22,000		$ 366,121,000	$ (122,632,000)	$ (1,852,000)	$ (96,112,000)	$ 145,547,000
Issuance of treasury stock upon purchase of common stock under employee stock purchase plan (in shares)	227,000
Issuance of treasury stock upon purchase of common stock under employee stock purchase plan		[1]		2,225,000		(330,000)	1,895,000
Issuance of treasury stock upon exercise of stock options, stock appreciation rights and restricted stock units by employees and directors (in shares)	663,000
Issuance of treasury stock upon exercise of stock options, stock appreciation rights and restricted stock units by employees and directors		[1]	59,000	6,500,000		(5,397,000)	$ 1,162,000
Purchase of treasury stock (in shares)	(389,000)						(389,000)
Purchase of treasury stock		[1]		(4,490,000)			$ (4,490,000)
Equity-based compensation expenses			5,861,000				5,861,000
Net loss						(3,003,000)	(3,003,000)
Change in accumulated other comprehensive income (loss)					(22,000)		(22,000)
Balance (in shares) at Dec. 31, 2017	22,433,000
Balance at Dec. 31, 2017	$ 22,000		372,041,000	(118,397,000)	(1,874,000)	(104,842,000)	146,950,000
Issuance of treasury stock upon purchase of common stock under employee stock purchase plan (in shares)	230,000
Issuance of treasury stock upon purchase of common stock under employee stock purchase plan		[1]		2,275,000		(271,000)	2,004,000
Issuance of treasury stock upon exercise of stock options, stock appreciation rights and restricted stock units by employees and directors (in shares)	618,000
Issuance of treasury stock upon exercise of stock options, stock appreciation rights and restricted stock units by employees and directors	$ 1,000		10,000	6,114,000		(5,387,000)	$ 738,000
Purchase of treasury stock (in shares)	(1,015,000)						(1,015,000)
Purchase of treasury stock	$ (1,000)			(12,317,000)			$ (12,318,000)
Equity-based compensation expenses			6,804,000				6,804,000
Net loss						(1,957,000)	(1,957,000)
Change in accumulated other comprehensive income (loss)					(450,000)		(450,000)
Adoption of accounting standard						94,000	94,000
Balance (in shares) at Dec. 31, 2018	22,266,000
Balance at Dec. 31, 2018	$ 22,000		378,855,000	(122,325,000)	(2,324,000)	(112,363,000)	141,865,000
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		[1]		2,066,000		(87,000)	1,979,000
Issuance of treasury stock upon exercise of stock options, stock appreciation rights and restricted stock units by employees and directors (in shares)	639,000
Issuance of treasury stock upon exercise of stock options, stock appreciation rights and restricted stock units by employees and directors	$ 1,000		48,000	6,397,000		(5,072,000)	$ 1,374,000
Purchase of treasury stock (in shares)							0
Equity-based compensation expenses			7,631,000				$ 7,631,000
Net loss						(1,190,000)	(1,190,000)
Change in accumulated other comprehensive income (loss)					1,435,000		1,435,000
Balance (in shares) at Dec. 31, 2019	23,111,000
Balance at Dec. 31, 2019	$ 23,000		$ 386,534,000	$ (113,862,000)	$ (889,000)	$ (118,712,000)	$ 153,094,000

[1] Represents an amount lower than $1.