Stockholders' Equity (Details 1) - Class A common stock [Member]	12 Months Ended
	Dec. 31, 2018 USD ($) $ / shares shares
Stock Repurchased During Period, Shares	1,055,057
First quarter 2018
Stock Repurchased During Period, Shares	530,693
Stock Repurchased During Period, Per Share | $ / shares	$ 7.92
Second quarter 2018
Stock Repurchased During Period, Shares	107,040
Stock Repurchased During Period, Per Share | $ / shares	$ 8.96
Third quarter 2018
Stock Repurchased During Period, Shares	0
Stock Repurchased During Period, Per Share | $ / shares	$ 0
Fourth quarter 2018
Stock Repurchased During Period, Shares	417,324
Stock Repurchased During Period, Per Share | $ / shares	$ 9.24
Publicly Announced Plan [Member] | First quarter 2018
Stock Repurchased During Period, Shares	530,693
Stock Repurchased Maximum Dollar Value of Shares | $	$ 20,795,897
Publicly Announced Plan [Member] | Second quarter 2018
Stock Repurchased During Period, Shares	637,733
Stock Repurchased Maximum Dollar Value of Shares | $	$ 19,837,157
Publicly Announced Plan [Member] | Third quarter 2018
Stock Repurchased During Period, Shares	637,733
Stock Repurchased Maximum Dollar Value of Shares | $	$ 19,837,157
Publicly Announced Plan [Member] | Fourth quarter 2018
Stock Repurchased During Period, Shares	1,055,057
Stock Repurchased Maximum Dollar Value of Shares | $	$ 15,982,102