Segment Reporting (Summary Of The Operating Information) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Revenues	$ 1,429,801	$ 1,387,778
Costs of revenue	243,848	230,656
Operating expenses	933,969	939,064
Total costs and expenses	1,177,817	1,169,720
Operating earnings (loss)	251,984	218,058
Domestic Segment
Segment Reporting Information [Line Items]
Revenues	1,258,456	1,221,992
Costs of revenue	215,241	205,694
Operating expenses	541,575	560,562
Total costs and expenses	756,816	766,256
Operating earnings (loss)	501,640	455,736
International Segment [Member]
Segment Reporting Information [Line Items]
Revenues	171,345	165,786
Costs of revenue	28,607	24,962
Operating expenses	71,422	61,614
Total costs and expenses	100,029	86,576
Operating earnings (loss)	71,316	79,210
Other
Segment Reporting Information [Line Items]
Operating expenses	320,972	316,888
Total costs and expenses	320,972	316,888
Operating earnings (loss)	$ (320,972)	$ (316,888)