CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Net of accumulated depreciation	$ 897	$ 897
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Preferred stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares, issued	23,643,277	23,499,635
Common stock, shares, outstanding	23,643,277	23,499,635
Common stock, par value	$ 0.01	$ 0.01