Income Taxes (Components Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 35,044	$ 39,290
Operating lease liabilities	26,628	0
Stock-based compensation	24,254	20,464
Uncertain tax positions	19,227	17,823
Employee benefits	9,392	15,048
Research and development credits	5,865	5,951
Other	6,309	4,121
Valuation allowance	(17,524)	(21,676)
Deferred tax assets	109,195	81,021
Other intangible assets	(99,193)	(38,787)
Operating lease right-of-use assets	(25,648)	0
Accounting method change	(21,396)	(31,626)
Deferred revenue	(13,744)	(12,021)
Property and equipment	(3,780)	(2,034)
Deferred tax liabilities	(163,761)	(84,468)
Net deferred tax liabilities	$ (54,566)	$ (3,447)