Allowance for Loan Losses, Allowance for Losses on Lending-Related Commitments and Impaired Loans 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, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Allowance for Covered Loan Losses [Roll Forward]
Balance at beginning of period	$ 1,667	$ 14,429	$ 10,092	$ 13,454
Provision for covered loan losses before benefit attributable to FDIC loss share agreements	(818)	(2,331)	(8,703)	515
Benefit attributable to FDIC loss share agreements	654	1,865	6,962	(412)
Net provision for covered loan losses	(164)	(466)	(1,741)	103
(Decrease) increase in FDIC indemnification asset	(654)	(1,865)	(6,962)	412
Loans charged-off	(293)	(3,237)	(5,346)	(8,294)
Recoveries of loans charged-off	2,099	4,063	6,612	7,249
Net recoveries (charge-offs)	1,806	826	1,266	(1,045)
Balance at end of period	$ 2,655	$ 12,924	$ 2,655	$ 12,924