CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current Assets
Accounts receivable, allowance for doubtful accounts	$ 1,747	$ 1,989
Stockholders' Equity:
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, authorized (in shares)	1,000,000	1,000,000
Preferred stock, issued (in shares)	0	0
Class A [Member]
Stockholders' Equity:
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, authorized (in shares)	10,000,000	10,000,000
Common stock, outstanding (in shares)	2,174,912	2,174,912
Common stock, treasury shares (in shares)	1,072,769	1,072,769
Class B [Member]
Stockholders' Equity:
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, authorized (in shares)	30,000,000	30,000,000
Common stock, outstanding (in shares)	9,701,977	9,686,777
Common stock, treasury shares (in shares)	3,218,307	3,218,307