Debt (Schedule Of Cash And Non-Cash Interest Expense) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Debt Instruments [Line Items]
Cash Interest	$ 42,248	$ 37,781
Non-Cash Interest	16,991	15,393
Convertible Senior Notes 1.875% Due 2013 [Member]
Debt Instruments [Line Items]
Cash Interest	2,508	2,567
Non-Cash Interest	8,913	8,320
Interest rate for senior notes	1.875%
Convertible Senior Notes 4.0% Due 2014 [Member]
Debt Instruments [Line Items]
Cash Interest	5,000	5,000
Non-Cash Interest	7,890	6,941
Interest rate for senior notes	4.00%
Senior Notes 8.0% Due 2016 [Member]
Debt Instruments [Line Items]
Cash Interest	7,500	7,500
Non-Cash Interest	81	75
Interest rate for senior notes	8.00%
Senior Notes 8.25% Due 2019 [Member]
Debt Instruments [Line Items]
Cash Interest	7,734	7,734
Non-Cash Interest	62	57
Interest rate for senior notes	8.25%
2010 Secured Tower Revenue Securities [Member]
Debt Instruments [Line Items]
Cash Interest	14,344	14,342
Revolving Credit Facility [Member]
Debt Instruments [Line Items]
Cash Interest	515	756
Term Loan [Member]
Debt Instruments [Line Items]
Cash Interest	4,715
Non-Cash Interest	45
Capitalized Interest [Member]
Debt Instruments [Line Items]
Cash Interest	$ (68)	$ (118)