Common Stock (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		18 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Sep. 20, 2017
Class of Stock [Line Items]
Proceeds from common stock issued		$ 103
ATM Program [Member]
Class of Stock [Line Items]
Shares issued, price per share		$ 10.40
Issuance of common stock, shares	0	12,334
Proceeds from common stock issued		$ 128
Net proceeds from common stock issue		$ 103
ATM Program, Since Inception [Member]
Class of Stock [Line Items]
Shares issued, price per share	$ 10.18		$ 10.18
Issuance of common stock, shares			197,478
Proceeds from common stock issued			$ 2,011
Net proceeds from common stock issue			$ 1,879
Maximum [Member] | ATM Program [Member]
Class of Stock [Line Items]
Equity distribution agreement, aggregate price of shares available for sale				$ 50,000
Minimum [Member] | ATM Program [Member]
Class of Stock [Line Items]
Public float required to sell shares of common stock				$ 75,000