Consolidated Statements Of Stockholders' Equity And Comprehensive Income (Loss) (USD $) In Thousands	Common Stock Issued [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at Jun. 30, 2010	$ 760	$ 1,023,081	$ (3,723)	$ 109,267	$ (15,640)	$ 1,113,745
Net income				51,986		51,986
Other comprehensive loss					(3,887)	(3,887)
Comprehensive income						48,099
Deemed capital contribution related to income taxes		4,068				4,068
Adjustments related to the transfer of liabilities from Cablevision in connection with certain pension plans as a result of the Distribution, net of taxes		(1,008)			40	(968)
Exercise of options		514				514
Share-based compensation expense		5,392				5,392
Excess tax benefit on share-based awards, net of deficiency		74				74
Balance at Dec. 31, 2010	760	1,032,121	(3,723)	161,253	(19,487)	1,170,924
Balance at Jun. 30, 2011	761	1,041,769	(10,279)	188,867	(15,233)	1,205,885
Net income				46,907		46,907
Other comprehensive loss					(6,572)	(6,572)
Comprehensive income						40,335
Exercise of options	2	1,735				1,737
Share-based compensation expense		10,579				10,579
Treasury stock acquired from acquisition of restricted shares			(534)			(534)
Excess tax benefit on share-based awards, net of deficiency		306				306
Balance at Dec. 31, 2011	$ 763	$ 1,054,389	$ (10,813)	$ 235,774	$ (21,805)	$ 1,258,308