Stockholders’ Equity (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Capital Stock Shares Authorised	120,000,000
Common Stock, Shares Authorized	79,999,997	79,999,997
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	2	2
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Special Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares, Issued	36,984,753	36,803,218
Common Stock, Shares, Outstanding	31,554,643	31,451,796
At-The-Market Equity Offering Program [Member]
Stock Issued During Period, Value, New Issues	$ 23,000
Stock Issuance Program, Maximum Amount Authorized			$ 12,000,000
Shares Issued, Price Per Share	$ 9.32
Stock Issuance Program, Remaining Amount Authorized	$ 10,800,000
At-The-Market Equity Offering Program [Member] | Common Stock [Member]
Stock Issued During Period, Shares, New Issues	2,492
Blank Check Preferred Stock [Member]
Preferred Stock, Shares Authorized	40,000,000	40,000,000
Blank Check Preferred Stock [Member] | Preferred Stock [Member]
Preferred Stock, Shares Authorized	40,000,000