Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Abstract]
Allowance for doubtful accounts	$ 10,907	$ 10,876
Accruals	10,811	11,682
Deferred revenue	4,845	4,822
Stock-based compensation	20,286	19,923
Other	15,505	12,944
Deferred tax assets	62,354	60,247
Less: Valuation allowance	(132)	(178)
Total deferred tax assets	62,222	60,069
Tax over book intangible asset amortization	(290,274)	(260,783)
Tax over book depreciation	(106,639)	(80,437)
Convertible debt interest	(72,185)	(64,156)
Other	(5,842)	(4,428)
Total deferred tax liabilities	(474,940)	(409,804)
Net deferred tax liabilities	$ (412,718)	$ (349,735)