Summary of Significant Accounting Policies Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2014
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss)	$ 116	$ 2,762	$ 1,482	$ (2,391)	$ (2,197)	$ 250	$ (1,767)	$ 572	$ 1,969	$ (3,143)	$ (5,970)	$ (5,970)
Net Income Allocated to Class A Stock									1,949	(3,112)		(5,910)
Net Income Allocated to Class B Stock									$ 20	$ (31)		$ (60)
Weighted Average Number of Shares Outstanding, Basic									50,082	50,082		50,082
Common Class A [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted Average Number of Shares Outstanding, Basic									49,080	49,080		49,080
Basic and diluted earnings (losses) per share (in dollars per share)									$ 0.04	$ (0.06)		$ (0.12)
Common Class B [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Weighted Average Number of Shares Outstanding, Basic and Diluted									1,002	1,002		1,002
Basic and diluted earnings (losses) per share (in dollars per share)									$ 0.02	$ (0.03)		$ (0.06)