Stockholders' Equity - Compensation Cost Related to Nonvested Awards (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Restricted Stock [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Number of shares issued	91,740	181,908
Value of shares issued	$ 347,700	$ 627,700
Weighted average estimated fair value	$ 3.79	$ 3.45
Restricted Stock Units [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Number of shares issued	139,497	10,260
Value of shares issued	$ 711,900	$ 55,100
Weighted average estimated fair value	$ 5.10	$ 5.37