Stockholders' Equity (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues	990,400
Proceeds from issuance of common shares, net	$ 30,591	$ 7,309
At-the-market equity issuance [Member]
Class of Stock [Line Items]
Proceeds from issuance of common shares, net	28,400
Gross Proceeds [Member] | At-the-market equity issuance [Member]
Class of Stock [Line Items]
Proceeds from issuance of common shares, net	$ 29,000