XML 20 R37.htm IDEA: XBRL DOCUMENT v2.4.0.6
STOCK BASED COMPENSATION (Details 3) (USD $)
 3 Months Ended 200 Months Ended 3 Months Ended 12 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Mar. 31, 2013
May 23, 2012
Mar. 31, 2013
Stock options
security
Mar. 31, 2012
Stock options
Dec. 31, 2012
Stock options
Mar. 31, 2013
Stock options
Minimum
Mar. 31, 2013
Stock options
Maximum
Stock-based compensation                  
Number of shares reserved for issuance       1,428,571          
Number of shares reserved for issuance before amendment       742,857          
Expiration period         10 years        
Vesting period 4 years       4 years        
Cash proceeds   $ 34,000 $ 267,000     $ 34,000      
Number of options outstanding                  
Options outstanding at the beginning of the period (in shares)         463,023        
Exercised (in shares)           77,062      
Options outstanding at the end of the period (in shares)         463,023   463,023    
Unvested at the end of the period (in shares)         62,024        
Vested and exercisable at the end of the period (in shares)         400,999        
Weighted average exercise price                  
Options outstanding at the beginning of the period (in dollars per share)         $ 26.61        
Options outstanding at the end of the period (in dollars per share)         $ 26.61   $ 26.61    
Unvested at the end of the period (in dollars per share)         $ 8.66        
Vested and exercisable at the end of the period (in dollars per share)         $ 29.39        
Weighted average remaining contractual term                  
Options outstanding         5 years 3 months 29 days   5 years 6 months 29 days    
Unvested at the end of the period         8 years 2 months 19 days        
Vested and exercisable at the end of the period         4 years 10 months 17 days        
Aggregate intrinsic value                  
Options outstanding         292,000   347,000    
Unvested at the end of the period         52,000        
Vested and exercisable at the end of the period         240,000        
Stock based compensation, additional disclosures                  
Forfeiture rate (as a percent)               0.00% 30.00%
Expense recognized due to revision of forfeiture rate           $ 1,000      
Change in forfeiture rate (as a percent) 0.00%   0.00%            
Number of Federal Reserve securities whose weighted average is used for calculation of weighted average risk-free interest rate         2