UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - Lien Category [Domain] - Long-term Debt, Type [Domain] - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Accounts receivable, allowance for doubtful accounts	$ 2,087	$ 2,125
Common Class A
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	10,476,190	10,476,190
Common stock, shares outstanding	10,476,190	10,476,190
Common Class B
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	15,000,000	15,000,000
Common stock, shares issued	14,951,625	14,951,625
Common stock, shares outstanding	14,951,625	14,951,625