Shareholders' Equity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Additional Paid-in Capital [Member]
Amount [Abstract]
Balance, Beginning period	$ 48,751	$ 47,874	$ 46,337
Restricted stock grant	1,524	877	1,537
Balance, Period end	50,275	48,751	47,874
Class A [Member]
Shares [Abstract]
Balance, Beginning period (in shares)	2,623,109	2,623,109	2,623,109
Restricted stock grant (in shares)	0	0	0
Balance, Period end (in shares)	2,623,109	2,623,109	2,623,109
Amount [Abstract]
Balance, Beginning period	112	112	112
Restricted stock grant	0	0	0
Balance, Period end	112	112	112
Stated value of common stock (in dollars per share)	$ 0.04
Class B [Member]
Shares [Abstract]
Balance, Beginning period (in shares)	12,225,348	12,187,009	12,109,878
Restricted stock grant (in shares)	64,687	38,339	77,131
Balance, Period end (in shares)	12,290,035	12,225,348	12,187,009
Amount [Abstract]
Balance, Beginning period	522	520	517
Restricted stock grant	2	2	3
Balance, Period end	$ 524	$ 522	$ 520
Stated value of common stock (in dollars per share)	$ 0.04