Annual report pursuant to Section 13 and 15(d)

Retirement plans (Details)

v2.4.0.6
Retirement plans (Details) (USD $)
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Compensation and Retirement Disclosure [Abstract]    
Maximum employer annual contribution per employee, percent 4.50%  
Contributions to plan $ 116,850 $ 115,120