STOCKHOLDERS' EQUITY, STOCK PLANS AND STOCK-BASED COMPENSATION EXPENSE (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010		Dec. 30, 2011
Stock Options [Member]
Share-based Compensation Arrangement By Share Based Payment Award [Line Items]
Option granted to employee vested period	3 years		3 years		3 years
Option granted contractual term	7 years		7 years		7 years
Shares Available for Grant [Roll Forward]
Beginning Balance (in shares)	1,644,356		474,537		1,005,447
Additional shares reserved (in shares)			1,910,000	[1]
Options granted (in shares)	(1,007,166)		(921,500)		(1,206,500)
Options cancelled (expired or forfeited) (in shares)	391,033		470,732		746,273
Stock awards granted (in shares)	(399,997)		(314,159)		(77,225)
Restricted stock units cancelled (expired or forfeited) (in shares)	81,257		24,746		6,542
Ending Balance (in shares)	709,483		1,644,356		474,537		1,005,447
Options Outstanding [Roll Forward]
Beginning Balance (in shares)	3,788,239		3,549,022		3,296,419
Options granted (in shares)	1,007,166		921,500		1,206,500
Options exercised (in shares)	(612,210)		(211,551)		(207,624)
Options cancelled (expired or forfeited) (in shares)	(391,033)		(470,732)		(746,273)
Ending Balance (in shares)	3,792,162		3,788,239		3,549,022		3,296,419
Number of shares exercisable (in shares)	2,221,657
Weighted Average Exercise Price [Roll Forward]
Beginning Balance (in dollars per share)	$ 9.44		$ 9.92		$ 10.93
Options granted (in dollars per share)	$ 8.97		$ 7.04		$ 8.61
Options exercised (in dollars per share)	$ 8.16		$ 7.00		$ 5.92
Options cancelled (expired or forfeited) (in dollars per share)	$ 10.37		$ 9.45		$ 13.40
Ending Balance (in dollars per share)	$ 9.42		$ 9.44		$ 9.92		$ 10.93
Weighted-Average Exercisable (in dollars per share)	$ 10.14
Weighted-Average Remaining Contractual life	4 years 2 months 12 days		4 years 3 months 18 days		4 years 7 months 6 days		4 years 4 months 24 days
Weighted-Average Remaining Contractual life exercisable	3 years
Aggregate Intrinsic Value	$ 5,100,000	[2]	$ 2,600,000	[2]	$ 400,000	[2]	$ 1,100,000	[2]
Aggregate Intrinsic Value	2,300,000	[2]
Closing price of company stock (in dollars per share)	$ 10.18		$ 9.00				$ 8.29		$ 7.45
Total intrinsic value	2,100,000		397,000		521,000
Restricted stock units [Member]
Weighted Average Exercise Price [Roll Forward]
Closing price of company stock (in dollars per share)	$ 10.18		$ 9.00		$ 7.45
ESPP [Member]
Employee Stock Purchase Plan [Abstract]
ESPP offering and purchase period	6 months
2004 Equity Incentive Plan [Member]
Share-based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation by share based payment fully vested stock awards grant date fair value	60,000
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	40,674		52,938		37,925
Employee Stock Purchase Plan [Abstract]
Shares of common stock reserved for issuance for employee purchase plan (in shares)	1,750,000
2004 Equity Incentive Plan [Member] | Stock Options [Member]
Share-based Compensation Arrangement By Share Based Payment Award [Line Items]
Terms of award	Options granted under the 1998 Plan and 2004 Equity Incentive Plan may be incentive stock options or non-statutory stock options. Stock purchase rights may also be granted under the 2004 Equity Incentive Plan. Incentive stock options may only be granted to employees. The Board of Directors determines the period over which options become exercisable. Options granted under the Plan to employees generally vest over a four year term from the vesting commencement date and become exercisable 25% on the first anniversary of the vesting commencement date and an additional 1/48th on the last day of each calendar month until all of the shares have become exercisable. During 2013, 2012 and 2011 the officers of the Company were granted options that vest over a three year term at the rate of 1/3rd on the one year anniversary of the vesting commencement date and 1/36th thereafter. The contractual term of the options granted in 2013, 2012 and 2011 was seven years.
Option granted to employee vested period	4 years
Option exercisable in hundredths	25.00%
2004 Equity Incentive Plan [Member] | Restricted stock units [Member]
Share-based Compensation Arrangement By Share Based Payment Award [Line Items]
Terms of award	In accordance with the 2004 Equity Incentive Plan, prior to 2012, the Company’s non-employee directors were granted $60,000 of grant date fair value, fully vested, stock awards annually on the date of the Company’s Annual Meeting of stockholders. Commencing with 2012, the Company’s non-employee directors get $60,000 of restricted stock units (RSUs) annually that cliff-vest on the one year anniversary of the grant date. In the year ended December 31, 2013 and 2012, the Company issued 40,674 and 52,938 shares of stock, respectively. In addition, in the year ended December 31, 2013 and 2013, the Company’s Board of Directors granted 148,004 and 95,250, respectively, of RSUs to certain members of the Company’s management. These RSUs vest at the rate of one-third on June 1of the year of grant, and one-third in each of the subsequent two years. The Company measured the fair market values of the underlying stock on the dates of grant and recognizes the stock-based compensation expense using the straight-line method over the vesting period.
Share based compensation by share based payment fully vested stock awards grant date fair value	$ 60,000
Additional restricted stock issued	148,004		95,250
2004 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares issued (in shares)	51,338		46,982
Common stock capital shares reserved for future issuance (in shares)	985,616
Employee Stock Purchase Plan [Abstract]
Shares of common stock	600,000
Percentage of outstanding shares of common stock (in hundredths)	2.00%
Purchase price of common stock (in hundredths)	85.00%
1998 Stock Plan [Member]
Employee Stock Purchase Plan [Abstract]
Shares of common stock reserved for issuance for employee purchase plan (in shares)	4,650,000
1998 Stock Plan [Member] | Stock Options [Member]
Share-based Compensation Arrangement By Share Based Payment Award [Line Items]
Terms of award	Options granted under the 1998 Plan and 2004 Equity Incentive Plan may be incentive stock options or non-statutory stock options. Stock purchase rights may also be granted under the 2004 Equity Incentive Plan. Incentive stock options may only be granted to employees. The Board of Directors determines the period over which options become exercisable. Options granted under the Plan to employees generally vest over a four year term from the vesting commencement date and become exercisable 25% on the first anniversary of the vesting commencement date and an additional 1/48th on the last day of each calendar month until all of the shares have become exercisable. During 2013, 2012 and 2011 the officers of the Company were granted options that vest over a three year term at the rate of 1/3rd on the one year anniversary of the vesting commencement date and 1/36th thereafter. The contractual term of the options granted in 2013, 2012 and 2011 was seven years.
Option granted to employee vested period	4 years
Option exercisable in hundredths	25.00%

[1] Approved by stock holders in 2012.

[2] Based on the closing stock price of the Company’s stock of $10.18 on December 31, 2013, $9.00 on December 31, 2012, $7.45 on December 30, 2011, and $8.29 on December 31, 2010.