Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Mar. 31, 2012	Jul. 07, 2010
Commitments and Contingencies Disclosure [Line Items]
Jury returned a verdict for breach of contract, awarding plaintiff damages		$ 269.4
Stipulation with plaintiff on prejudgment interest award		50
Reduction in unrecognized tax benefits including interest and penalties from settlements with state and federal taxing authorities	93
Unrecognized tax benefits expected reduction due to resolutions of open tax matters	52
Broadcast Programming
Commitments and Contingencies Disclosure [Line Items]
Long-term receivables, net of allowance for credit losses	900
Mortgage Receivable
Commitments and Contingencies Disclosure [Line Items]
Long-term receivables, net of allowance for credit losses	500
Allowance for credit losses related to long-term receivables, percentage	4.00%
Guarantee Obligations
Commitments and Contingencies Disclosure [Line Items]
Guaranteed obligations	355
Remaining debt service obligation guaranteed, principal	84
Financial Guarantee
Commitments and Contingencies Disclosure [Line Items]
Guaranteed obligations	$ 600