Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss)	$ (3,802)	$ 37
Net Income Allocated to Class A Common Stock	(3,764)	37
Net Income Allocated to Class B Common Stock	$ (38)	$ 0
Common Stock Class A [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted Average Number of Shares Outstanding, Basic	49,229	49,080
Weighted Average Number of Shares Outstanding, Diluted	49,267	49,080
Earnings Per Share, Basic and Diluted	$ (0.08)	$ 0.00
Common Stock Class B [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted Average Shares Outstanding, Basic and Diluted	1,002	1,002
Earnings Per Share, Basic and Diluted	$ (0.04)	$ 0.00