Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Assets
Account receivable, allowance	$ 615	$ 538
Property and equipment, accumulated depreciation	$ 15,835	$ 15,184
Class A (voting) [Member]
Shareholders' equity:
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	3,000,000	3,000,000
Common stock, shares outstanding (in shares)	2,623,109	2,623,109
Class B (non-voting) [Member]
Shareholders' equity:
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	20,000,000	20,000,000
Common stock, shares outstanding (in shares)	12,304,191	12,290,035