Annual report pursuant to Section 13 and 15(d)

Income taxes - Schedule of provision for income tax expense (Details)

v3.7.0.1
Income taxes - Schedule of provision for income tax expense (Details) - USD ($)
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Current tax expense:    
Federal $ 0 $ 0
State and local 61,920 533,815
Foreign 259,987 207,952
Total current tax expense 321,907 741,767
Deferred tax expense (benefit):    
Federal 7,654,364 (7,631,243)
State and local 2,393,893 (2,376,233)
Foreign (252) (50,778)
Total deferred tax expense (benefit) 10,048,005 (10,058,254)
Total income tax expense (benefit) $ 10,369,912 $ (9,316,487)