Schedule II - Valuation and Qualifiying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, Beginning of Year	$ 1,630	$ 1,502	$ 1,351
Additions Charged to Revenues, Costs and Expenses	997	1,196	773
Additions/(Deductions) Charged to Balance Sheet Accounts	(109)	(334)	(144)
(Deductions) Charged to Revenues, Costs and Expenses	(901)	(734)	(478)
Balance, End of Year	1,617	1,630	1,502
Reserve for Audience Underdelivery [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, Beginning of Year	0	0	2,857
Additions Charged to Revenues, Costs and Expenses	0	0	2,065
Additions/(Deductions) Charged to Balance Sheet Accounts	0	0	(3,605)
(Deductions) Charged to Revenues, Costs and Expenses	0	0	(1,317)
Balance, End of Year	0	0	0
Valuation Allowance of Deferred Tax Assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, Beginning of Year	83,846	76,963	73,282
Additions Charged to Revenues, Costs and Expenses	5,031	6,883	3,681
Additions/(Deductions) Charged to Balance Sheet Accounts	0	0	0
(Deductions) Charged to Revenues, Costs and Expenses	0	0	0
Balance, End of Year	$ 88,877	$ 83,846	$ 76,963