Calculation Of Net Income Per Share (Weighted-Average Shares Used In Calculation Of Basic And Diluted EPS) (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Weighted-average number of common shares outstanding	111,664	114,655	112,389	115,456
Unvested RSUs and ESPP	129	176	141	243
Shares used to compute diluted net income per share	111,793	114,831	112,530	115,699