Stockholder's Equity (Summary Of Stock Option Plan Activity) (Details) - $ / shares	12 Months Ended			105 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2021
Options Outstanding
Granted (in shares)				11,375,531
Exercised (in shares)	(1,305,107)	(1,630,664)	(2,325,073)
Outstanding as of End of Period (in shares)	5,173,270			5,173,270
Options Exercisable (in shares)	1,693,805			1,693,805
Stock Option Plan
Options Outstanding
Outstanding as of Beginning of Period (in shares)	5,914,757	6,807,217
Granted (in shares)	741,510	902,263
Exercised (in shares)	(1,305,107)	(1,630,664)
Cancelled/forfeited (in shares)	(177,890)	(164,059)
Outstanding as of End of Period (in shares)	5,173,270	5,914,757	6,807,217	5,173,270
Options Exercisable (in shares)	1,693,805	1,885,241		1,693,805
Exercise Price
Outstanding as of Beginning of Period (in dollars per share)	$ 26.73	$ 24.89
Granted (in dollars per share)	48.00	38.00
Exercised (in dollars per share)	24.34	25.18
Cancelled/forfeited (in dollars per share)	31.22	27.64
Outstanding as of End of Period (in dollars per share)	30.23	26.73	$ 24.89	$ 30.23
Exercisable (in dollars per share)	$ 25.11	$ 24.23		$ 25.11
Remaining Life
Outstanding	6 years 29 days	6 years 2 months 19 days	6 years 1 month 2 days
Granted	9 years	9 years
Exercisable	4 years 8 months 4 days	4 years 8 months 15 days