Cash Flows (Summary Of Non-Cash Activities And Other Supplemental Data) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Noncash Investing and Financing Items [Abstract]
Deemed capital contributions related to the utilization of Cablevision tax losses	$ (1,448)	$ 37,912
Deemed capital contribution, net related to adjustments to liability for uncertain tax positions and net deferred tax assets as a result of the Distribution	(1,148)	44,508
Capital distribution for the transfer of a promissory note receivable to Cablevision	0	(17,113)
Deemed capital distribution to Cablevision related to employee benefit plans as a result of the Distribution	0	(6,602)
Deemed capital distribution associated with the issuance of debt to related party	0	(1,250,000)	(1,250,000)
Deemed capital contribution related to the allocation of Cablevision share-based compensation expense	0	8,343
Leasehold improvements paid by landlord	2,071	150
Increase in capital lease obligations and related assets	1,399	39
Cash interest paid - continuing operations	99,193	64,300
Income taxes paid, net - continuing operations	$ 19,892	$ 8,289