Shareholders' Equity And Earnings Per Share (Computation Of Basic And Diluted Earnings Per Common Share) (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Equity [Abstract]
Net income	$ 142,961	$ 109,137	$ 364,865	$ 367,394
Less: Preferred stock dividends	6,991	6,991	20,973	20,973
Net income applicable to common shares	$ 135,970	$ 102,146	$ 343,892	$ 346,421
Weighted average common shares outstanding (in shares)	60,738	57,000	58,679	56,985
Dilutive potential common shares (in shares)	837	753	814	728
Weighted average common shares and effect of dilutive potential common shares (in shares)	61,575	57,753	59,493	57,713
Net income per common share:
Basic (usd per share)	$ 2.24	$ 1.79	$ 5.86	$ 6.08
Diluted (usd per share)	$ 2.21	$ 1.77	$ 5.78	$ 6.00