Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss)	$ (4,565)	$ (3,802)	$ (2,558)	$ 37	$ (8,367)	$ (2,521)
Common Stock Class A [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net Income (Loss) Available to Common Stockholders, Basic	(4,519)		(2,532)		(8,283)	(2,496)
Net Income (Loss) Available to Common Stockholders, Diluted	$ (4,519)		$ (2,532)		$ (8,283)	$ (2,496)
Weighted Average Number of Shares Outstanding, Basic	49,229		49,080		49,229	49,080
Weighted Average Number of Shares Outstanding, Diluted	49,280		49,109		49,280	49,109
Basic and diluted earnings (loss) per share (in dollars per share)	$ (0.09)		$ (0.05)		$ (0.17)	$ (0.05)
Common Stock Class B [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net Income (Loss) Available to Common Stockholders, Basic	$ (46)		$ (26)		$ (84)	$ (25)
Net Income (Loss) Available to Common Stockholders, Diluted	$ (46)		$ (26)		$ (84)	$ (25)
Weighted Average Shares Outstanding, Basic and Diluted	1,002		1,002		1,002	1,002
Basic and diluted earnings (loss) per share (in dollars per share)	$ (0.04)		$ (0.03)		$ (0.08)	$ (0.03)