Acquisitions - Narrative (Details)
1 Months Ended 3 Months Ended 6 Months Ended
Jun. 01, 2015
USD ($)
Employee_grantedoptions
$ / shares
shares
Jun. 30, 2015
USD ($)
Jun. 30, 2016
USD ($)
shares
Mar. 31, 2016
USD ($)
Jun. 30, 2015
USD ($)
Jun. 30, 2016
USD ($)
shares
Jun. 30, 2015
USD ($)
shares
Dec. 31, 2015
USD ($)
Business Acquisition [Line Items]                
Echo share price | $ / shares $ 32.52              
Marketability discount percentage applied 10.00%              
Goodwill     $ 307,314,171     $ 307,314,171   $ 308,490,588
Contingent asset due from seller     32,006     (32,006) $ 0  
Receipt of contingent consideration due from seller     750,000     750,000 0  
Stock-based compensation expense     3,793,083   $ 2,613,768 $ 9,109,921 $ 4,504,835  
Restricted stock                
Business Acquisition [Line Items]                
Grants in period, other than options (in shares) | shares           236,375 674,947  
Contingent consideration                
Business Acquisition [Line Items]                
Contingent consideration receivable     $ 400,000     $ 400,000    
Contingent consideration | Maximum                
Business Acquisition [Line Items]                
Contingent consideration receivable $ 1,500,000              
Command Transportation, LLC                
Business Acquisition [Line Items]                
Fair value of total consideration transferred $ 407,706,392              
Equity portion of purchase price (in shares) | shares 503,829              
Goodwill $ 225,304,568              
Contingent asset due from seller $ (1,176,417)     $ (1,200,000)        
Command Transportation, LLC | Restricted stock                
Business Acquisition [Line Items]                
Grants in period, other than options (in shares) | shares 335,882              
Number of employees granted shares | Employee_grantedoptions 33              
Command Transportation, LLC | Restricted stock | Sellers with new Employment Agreements                
Business Acquisition [Line Items]                
Grants in period, other than options (in shares) | shares 100,766              
Number of employees granted shares | Employee_grantedoptions 2              
Award vesting period 3 years              
Number of shares of restricted common stock and performance stock outstanding | shares     33,588     33,588    
Stock-based compensation expense   $ 1,000,000 $ 2,100,000     $ 5,200,000    
Command Transportation, LLC | Performance Shares | Sellers with new Employment Agreements                
Business Acquisition [Line Items]                
Grants in period, other than options (in shares) | shares 67,178              
Number of shares of restricted common stock and performance stock outstanding | shares     33,589     33,589