Restructuring charges (Tables)
 12 Months Ended
Dec. 31, 2013
Restructuring Charges [Abstract]  
Restructuring and related costs
 
Accrued as of January 1, 2013
 
Charges
 
Payments
 
Non-Cash Items
 
Accrued as of December 31, 2013
Severance Charges
$
—

 
$
324,615

 
$
(206,385
)
 
$
—

 
$
118,230

Asset Impairments
—

 
188,329

 
—

 
(188,329
)
 
—

 
$
—

 
$
512,944

 
$
(206,385
)
 
$
(188,329
)

$
118,230