Description Of Business And Summary Of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Capitalized Computer Software, Additions	$ 11,900	$ 14,700
Advertising expenses	12,800	15,200	$ 27,400
Derivative, Notional Amount	26,300
Deferred Tax Liabilities, Other	$ 3,608	$ 7,495
Building Improvements [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property and equipment (years)	10 years
Maximum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
RegistrationTerm	ten
Maximum [Member] | Buildings [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property and equipment (years)	47 years
Maximum [Member] | Computer Equipment, Purchased Software, Office Equipment, And Furniture And Fixtures [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property and equipment (years)	5 years
Minimum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
RegistrationTerm	one
Minimum [Member] | Buildings [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property and equipment (years)	35 years
Minimum [Member] | Computer Equipment, Purchased Software, Office Equipment, And Furniture And Fixtures [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property and equipment (years)	3 years