Earnings Per Share (Computation Of Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share [Abstract]
Net income		$ 163,575	$ 157,539
Preferred dividends		9,320	9,320
Net income available to common shareholders		$ 154,255	$ 148,219
Average shares used in basic computation		104,275	108,754
Dilutive effect of stock options and units	[1]	5,710	6,636
Average shares used in diluted computation		109,985	115,390
Basic		$ 1.48	$ 1.36
Diluted		$ 1.4	$ 1.28

[1] Diluted earnings per share is computed on the basis of the weighted-average number of shares of common stock plus the effect of dilutive potential common shares outstanding during the period using the treasury stock method. Diluted earnings per share include units.