COMPUTATION OF EARNINGS (LOSS) PER SHARE (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Information related to EPS computation
Series A 3% Redeemable Convertible Preferred Stock, dividend rate (as a percent)	3.00%	3.00%	3.00%	3.00%	3.00%
Net income allocated to common stockholders (in dollars)	$ 9,332	$ 9,085	$ 11,892	$ 32,541
Basic:
Weighted-average common shares outstanding	28,374	27,714	28,239	27,698
Basic (in dollars per share)	$ 0.27	$ 0.27	$ 0.35	$ 0.97
Diluted:
Weighted-average shares outstanding used in basic calculation	28,374	27,714	28,239	27,698
Dilutive effect of options	271	248	282	221
Dilutive effect of unvested restricted stock	323	125	367	177
Weighted-average common stock and common stock equivalents	28,968	28,087	28,888	28,096
Diluted (in dollars per share)	$ 0.27	$ 0.27	$ 0.34	$ 0.96
Common Stock
Information related to EPS computation
Net income allocated to common stockholders (in dollars)	7,746	7,518	9,871	26,928
Series A 3% Redeemable Convertible Preferred Stock
Information related to EPS computation
Series A 3% Redeemable Convertible Preferred Stock, dividend rate (as a percent)	3.00%	3.00%	3.00%	3.00%
Net income allocated to common stockholders (in dollars)	$ 2,526	$ 2,467	$ 4,809	$ 8,279
Diluted:
Stock issuable upon conversion of the Series A Preferred Stock	5,806	5,806	5,806	5,806
Stock awards excluded from calculation as their effect would be anti-dilutive	577	937	563	880

Number of shares issuable upon conversion of each share of convertible preferred stock.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of non-vested restricted stock arrangements.

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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The earnings attributable to each security on the basis that all of the earnings for the period had been distributed (to the extent that each security may share in earnings). This is the earnings amount which reflects the participation rights in undistributed earnings of each security.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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