Trade and Barter Transactions (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Trade and Barter Transactions (Textual) [Abstract]
Trade and barter revenue	$ 5.1	$ 5.6	$ 5.6
Trade and barter expenses	$ 5.1	$ 5.6	$ 5.7