Equity, Common Stock (Details) - Common Stock [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Aug. 31, 2018	Jul. 30, 2018
Common Stock [Abstract]
Number of shares of common stock sold (in shares)	467,928	560,338	1,320,921	1,751,689
Universal Shelf Registration Statement [Member] | Maximum [Member]
Common Stock [Abstract]
Securities offered for sale, aggregate value							$ 100,000
ATM Agreement [Member]
Common Stock [Abstract]
Number of shares of common stock sold (in shares)	467,928				1,028,266
Average sales price per common share (in dollars per share)	$ 6.28				$ 5.71
Aggregate proceeds from sales of common stock	$ 2,937				$ 5,873
Sales commissions, fees and other costs associated with issuance of common stock	88				176
ATM Agreement [Member] | Maximum [Member]
Common Stock [Abstract]
Securities offered for sale, aggregate value	$ 31,584				$ 31,584	$ 50,000