Income Taxes (Summary Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Income Tax Expense (Benefit) [Abstract]
Net operating loss carryforwards	$ 34,422	$ 20,157
Deductible goodwill and intangible assets	7,761	8,909
Tax credit carryforwards	0	6,213
Deferred revenue, accruals and reserves	87,235	106,234
Capital loss carryforwards and book impairment of investments	3,400	5,749
Other	5,234	4,439
Total deferred tax assets	138,052	151,701
Valuation allowance	(20,815)	(15,882)
Net deferred tax assets	117,237	135,819
Property and equipment	(21,522)	(42)
Non-deductible acquired intangibles	0	(148)
Convertible debentures	(424,488)	(390,125)
Other	(5,984)	(3,417)
Deferred Tax Liabilities, Gross	451,994	393,732
Total deferred tax liabilities	$ 334,757	$ 257,913