Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred Tax Assets:
Accruals and allowances	$ 25,041	$ 20,743
Net operating loss carryforwards	1,352	1,267
Stock-based compensation	5,374	6,381
Operating lease liability	5,303	6,456
Deferred revenue	641	1,449
Tax credit carryforwards		896
Acquired intangibles	33,860	31,708
Depreciation and amortization	1,651	1,639
Other	3,285	1,080
Total deferred tax assets	76,507	71,619
Deferred Tax Liabilities:
Right of use asset	(4,264)	(5,218)
Other	(987)	(1,053)
Total deferred tax liabilities	(5,251)	(6,271)
Valuation Allowance	(2,933)	(6,418)
Net deferred tax assets	68,323	58,930
Valuation allowance, net of federal tax	$ 2,900	$ 5,200