Acquisitions (Details) (USD $)	Sep. 30, 2012	Sep. 30, 2012 RealGravity [Member]	Jan. 31, 2012 RealGravity [Member]	Apr. 30, 2012 Travel Channel International [Member]
Business Acquisition [Line Items]
Cash consideration			$ 20,000,000	$ 107,000,000
Cash acquired in acquisition				7,600,000
Contingent consideration liability	9,300,000		8,300,000
Fair values of assets acquired and liabilities assumed [Abstract]
Accounts receivable				6,545,000
Other current assets				1,406,000
Programs and program licenses				9,164,000
Property and equipment				475,000
Amortizable intangible assets				59,977,000
Current liabilities				(4,456,000)
Deferred income taxes				(15,243,000)
Total identifiable net assets				57,868,000
Goodwill		21,600,000		41,599,000
Net purchase price				$ 99,467,000