Quarterly report pursuant to Section 13 or 15(d)

Employee Benefit 401(k) Plans And Deferred Retirement Compensation Agreements (Details)

v2.4.0.6
Employee Benefit 401(k) Plans And Deferred Retirement Compensation Agreements (Details) (USD $)
3 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]    
Minimum employee subscription rate, percentage of compensation 1.00%  
Maximum employee subscription rate, percentage of compensation 60.00%  
Employee pre-tax contributions vested percentage 100.00%  
Vesting rate 20.00%  
Percentage vested after total service period 100.00%  
Employees' vesting rights Participants are always 100 percent vested in their pre-tax contributions and will begin vesting in any matching or profit sharing contributions made on their behalf after two years of service with the Company at a rate of 20 percent per year, becoming 100 percent vested after a total of six years of service with the Company.  
Expenses for employee benefit plan $ 38,000 $ 0
Shares granted 68,139  
Fair value of awards $ 28.65  
Period upon which stock units become payable following a triggering event 30 days  
Minimum [Member]
   
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]    
Employer contribution vesting period 2 years  
Maximum [Member]
   
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]    
Employer contribution vesting period 6 years  
Messr Hersh [Member]
   
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]    
Amount of annual employer contribution to deferred retirement compensation 500,000  
Messr Lefkowitz [Member]
   
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]    
Amount of annual employer contribution to deferred retirement compensation 160,000  
Messr Thomas [Member]
   
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]    
Amount of annual employer contribution to deferred retirement compensation $ 100,000  
Deferred Retirement Compensation Units [Member]
   
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]    
Shares granted 25,333  
Fair value of awards $ 25.9825