Intangible Assets - Intangible Assets (Details) (USD $)
9 Months Ended
Sep. 30, 2012
Sep. 30, 2011
Dec. 31, 2011
Summary of amortizable intangible assets:      
Finite-lived intangible assets, gross $ 14,033,923   $ 12,845,322
Less accumulated amortization (8,051,186)   (6,563,870)
Intangible assets, net 5,982,737   6,281,452
Weighted average useful life 6 years 6 months    
Amortization of expense 1,487,316 1,815,410  
Estimated amortization expense for hte next five years and thereafter:      
Remainder of 2012 482,556    
2013 1,609,150    
2014 1,292,807    
2015 1,070,811    
2016 745,095    
Thereafter 782,318    
Intangible assets, net 5,982,737   6,281,452
Customer relationships
     
Summary of amortizable intangible assets:      
Finite-lived intangible assets, gross 13,704,923   12,516,322
Weighted average useful life 6 years 6 months    
Non-compete agreements
     
Summary of amortizable intangible assets:      
Finite-lived intangible assets, gross 139,000   139,000
Weighted average useful life 2 years 10 months 24 days    
Trade names
     
Summary of amortizable intangible assets:      
Finite-lived intangible assets, gross $ 190,000   $ 190,000
Weighted average useful life 3 years