Stockholder's Equity (Summary Of Stock Option Plan Activity) (Details) - $ / shares	12 Months Ended			104 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2022
Options Outstanding
Granted (in shares)				11,678,969
Exercised (in shares)	(346,992)	(1,305,107)	(1,630,664)
Outstanding as of End of Period (in shares)	5,374,736			5,374,736
Options Exercisable (in shares)	2,437,636			2,437,636
Stock Option Plan
Options Outstanding
Outstanding as of Beginning of Period (in shares)	5,173,270	5,914,757
Granted (in shares)	713,438	741,510
Exercised (in shares)	(346,992)	(1,305,107)
Cancelled/forfeited (in shares)	(164,980)	(177,890)
Outstanding as of End of Period (in shares)	5,374,736	5,173,270	5,914,757	5,374,736
Options Exercisable (in shares)	2,437,636	1,693,805		2,437,636
Exercise Price
Outstanding as of Beginning of Period (in dollars per share)	$ 30.23	$ 26.73
Granted (in dollars per share)	62.00	48.00
Exercised (in dollars per share)	26.78	24.34
Cancelled/forfeited (in dollars per share)	40.00	31.22
Outstanding as of End of Period (in dollars per share)	34.37	30.23	$ 26.73	$ 34.37
Exercisable (in dollars per share)	$ 27.14	$ 25.11		$ 27.14
Remaining Life
Outstanding	5 years 7 months 28 days	6 years 29 days	6 years 2 months 19 days
Granted	9 years	9 years
Exercisable	4 years 3 months 18 days	4 years 8 months 4 days