Consolidated Balance Sheets Parenthetical - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts receivable, net of allowance of $1,433 and $1,079, respectively	$ 1,079	$ 1,433
Long-term debt, less current portion (net of deferred financing costs of $8,006 and $6,803, respectively)	$ 6,803	$ 8,006
Common shares authorized (in shares)	400,000,000
Common Class A
Common shares authorized (in shares)	300,000,000	300,000,000
Common shares outstanding (in shares)	13,819,639	13,735,690
Common stock, shares, issued (in shares)	13,819,639	13,735,690
Common stock par value par value (usd per share)	$ 0.01	$ 0.01
Common Class B
Common shares authorized (in shares)	50,000,000	50,000,000
Common shares outstanding (in shares)	3,022,484	3,022,484
Common stock, shares, issued (in shares)	3,022,484	3,022,484
Common stock par value par value (usd per share)	$ 0.01	$ 0.01
Common Class C
Common shares authorized (in shares)	50,000,000	50,000,000
Common shares outstanding (in shares)	1,636,341	1,636,341
Common stock, shares, issued (in shares)	1,636,341	1,636,341
Common stock par value par value (usd per share)	$ 0.01	$ 0.01