Equity And Stock-Based Compensation (Schedule Of Stock Options Outstanding And Exercisable) (Details) (USD $)	3 Months Ended			12 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Class A [Member]	Dec. 31, 2012 Class A [Member]	Mar. 31, 2013 Class B [Member]	Dec. 31, 2012 Class B [Member]
Equity And Stock-Based Compensation [Line Items]
Common Stock Options Outstanding, Beginning balance			672,350	622,350	185,100	185,100
Common Stock Options Outstanding, Granted			20,000	206,000
Common Stock Options Outstanding, Exercised	0	(40,000)		(136,000)
Common Stock Options Outstanding, Expired				(20,000)
Common Stock Options Outstanding, Ending balance			692,350	672,350	185,100	185,100
Weighted Average Exercise Price of Options Outstanding, Beginning price			$ 6.24	$ 5.65	$ 9.90	$ 9.90
Weighted Average Exercise Price of Options Outstanding, Granted	$ 5.55	$ 4.44	$ 5.55	$ 5.94
Weighted Average Exercise Price of Options Outstanding, Exercised				$ 4.68
Weighted Average Exercise Price of Options Outstanding, Expired				$ 3.75
Weighted Average Exercise Price of Options Outstanding, Ending price			$ 6.22	$ 6.24	$ 9.90	$ 9.90
Common Stock Exercisable Options, Outstanding Beginning balance			546,350	544,383	185,100	167,550
Common Stock Exercisable Options, Outstanding Ending balance			566,350	546,350	185,100	185,100
Weighted Average Price of Exercisable Options, Outstanding Beginning balance			$ 6.26	$ 5.86	$ 9.90	$ 10.05
Weighted Average Price of Exercisable Options, Outstanding Ending balance			$ 6.23	$ 6.26	$ 9.90	$ 9.90