Summary Of Significant Accounting Policies (Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Net income	$ 451,295	$ 419,375	$ 259,251
Weighted average shares outstanding - basic	84,259	83,973	84,988
Dilutive effect of stock plans	1,666	1,940	1,866
Weighted average shares outstanding - diluted	85,925	85,913	86,854
Basic earnings per share	$ 5.36	$ 4.99	$ 3.05
Diluted earnings per share	$ 5.25	$ 4.88	$ 2.98
Anti-dilutive shares	14	7	84