Selling Arrangement (Details) (Selling Agreement, USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2011
Selling Agreement
Selling Arrangement
Payment for arrangement to sell signs					$ 4,000,000
Term of arrangement			10 years
Amortization expense	100,000	100,000	300,000	300,000
2013	400,000		400,000
2014	400,000		400,000
2015	400,000		400,000
2016	400,000		400,000
2017	$ 400,000		$ 400,000