Annual report pursuant to Section 13 and 15(d)

Geographic Information (Details)

v2.4.0.6
Geographic Information (Details) (USD $)
 3 Months Ended 12 Months Ended
Dec. 31, 2012
Sep. 30, 2012
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2011
Sep. 30, 2011
Jun. 30, 2011
Mar. 31, 2011
Dec. 31, 2010
Sep. 30, 2010
Jun. 30, 2010
Mar. 31, 2010
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Revenues from External Customers and Long-Lived Assets [Line Items]                              
Assets $ 675,472,003       $ 645,597,467       $ 582,450,973       $ 675,472,003 $ 645,597,467 $ 582,450,973
Net revenues 156,591 163,906 164,100 146,573 188,494 227,804 165,482 146,420 179,342 191,901 141,355 105,629 631,170,565 728,200,318 618,226,659
United States
                              
Revenues from External Customers and Long-Lived Assets [Line Items]                              
Assets 597,558,426       576,695,791               597,558,426 576,695,791  
Net revenues                         563,746,226 615,583,995 514,372,208
Canada
                              
Revenues from External Customers and Long-Lived Assets [Line Items]                              
Assets 77,055,425       68,321,537               77,055,425 68,321,537  
Net revenues                         60,589,842 110,594,062 101,870,281
Other
                              
Revenues from External Customers and Long-Lived Assets [Line Items]                              
Assets 858,152       580,139               858,152 580,139  
Net revenues                         $ 6,834,497 $ 2,022,261 $ 1,984,170