Shareholders' Equity And Earnings Per Share (Computation Of Basic And Diluted Earnings Per Common Share) (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Shareholders' Equity and Earnings Per Share Disclosure [Abstract]
Net income	$ 34,500	$ 32,052
Less: Preferred stock dividends and discount accretion	1,581	2,616
Net income applicable to common shares	32,919	29,436
Add: Dividends on convertible preferred stock, if dilutive	1,581	2,581
Net income applicable to common shares-Diluted	$ 34,500	$ 32,017
Weighted average common shares outstanding	46,195	36,976
Effect of dilutive potential common shares
Common stock equivalents	1,434	7,443
Convertible preferred stock, if dilutive	3,075	5,020
Total dilutive potential common shares	4,509	12,463
Average common shares and dilutive common shares	50,704	49,439
Net income per common share-Basic	$ 0.71	$ 0.80
Net income per common share-Diluted	$ 0.68	$ 0.65