Income Taxes Income Taxes (Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Abstract]
Deferred Tax Assets, Operating Loss Carryforwards	$ 29,317	$ 59,806
Deferred Tax Assets, Tax Credit Carryforwards	2,645	16,281
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities	3,165	14,759
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Allowance for Doubtful Accounts	1,570	2,624
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	6,476	5,631
Deferred Tax Assets, Property, Plant and Equipment	1,881	2,195
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Impairment Losses	48	74
Deferred Tax Assets, Deferred Income	728	2,361
Deferred Tax Assets, State Taxes	1,777	1,758
Deferred Tax Assets, Other	14,165	9,227
Deferred Tax Assets, Gross	61,772	114,716
Deferred Tax Assets, Valuation Allowance	(197)	(12,028)
Deferred Tax Assets, Net of Valuation Allowance	61,575	102,688
Deferred Tax Liabilities, Intangible Assets	(70,252)	(98,830)
Deferred Tax Liabilities, Prepaid Insurance	(616)	(246)
Deferred Tax Liability, Convertible Debt	(27,504)	(36,592)
Deferred Tax Liabilities, Foreign Other	(1,467)	(2,088)
Deferred Tax Liabilities, Net	(99,839)	(137,756)
Deferred Tax Assets, Net	$ (38,264)	$ (35,068)