Allowance for Loan Losses, Allowance for Losses on Lending-Related Commitments and Impaired Loans (Summary Of Activity In The Allowance For Covered Loan Losses) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Allowance for Covered Loan Losses [Roll Forward]
Balance at beginning of period	$ 14,429	$ 20,560	$ 13,454	$ 12,977
Provision for covered loan losses before benefit attributable to FDIC loss share agreements	(2,331)	3,096	515	25,916
Benefit attributable to FDIC loss share agreements	1,865	(2,489)	(412)	(20,766)
Net provision for covered loan losses	(466)	607	103	5,150
(Decrease) increase in FDIC indemnification asset	(1,865)	2,489	412	20,766
Loans charged-off	(3,237)	(1,736)	(8,294)	(17,052)
Recoveries of loans charged-off	4,063	6	7,249	85
Net recoveries (charge-offs)	826	(1,730)	(1,045)	(16,967)
Balance at end of period	$ 12,924	$ 21,926	$ 12,924	$ 21,926