Covered Assets (Changes In Allowance For Covered Loan Losses) (Detail) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Balance at beginning of period					$ 25,939,000
Balance at end of period	21,733,000				21,733,000
Provision for credit losses	365,000		632,000		(299,000)		240,000
Non-reimbursable portion under the loss share agreement	20.00%		20.00%		20.00%		20.00%
Covered Assets [Member]
Balance at beginning of period	26,323,000		19,738,000		25,939,000		15,334,000
Loans charged-off	(602,000)				(604,000)		(1,000)
Recoveries on loans previously charged-off	242,000		327,000		302,000		373,000
Net (charge-offs) recoveries	(360,000)		327,000		(302,000)		372,000
(Release) provision for covered loan losses	(4,230,000)	[1]	(3,161,000)	[1]	(3,904,000)	[2]	1,198,000	[2]
Balance at end of period	21,733,000		16,904,000		21,733,000		16,904,000
Purchased Impaired Loans [Member] | Covered Assets [Member]
Balance at beginning of period	12,871,000		11,690,000		14,727,000		8,601,000
Loans charged-off	(580,000)				(580,000)
Recoveries on loans previously charged-off	193,000		326,000		239,000		329,000
Net (charge-offs) recoveries	(387,000)		326,000		(341,000)		329,000
(Release) provision for covered loan losses	(3,962,000)	[1]	(3,199,000)	[1]	(5,864,000)	[2]	(113,000)	[2]
Balance at end of period	8,522,000		8,817,000		8,522,000		8,817,000
Purchased Nonimpaired Loans [Member] | Covered Assets [Member]
Balance at beginning of period	13,452,000		8,048,000		11,212,000		6,733,000
Loans charged-off	(22,000)				(24,000)		(1,000)
Recoveries on loans previously charged-off	49,000		1,000		63,000		44,000
Net (charge-offs) recoveries	27,000		1,000		39,000		43,000
(Release) provision for covered loan losses	(268,000)	[1]	38,000	[1]	1,960,000	[2]	1,311,000	[2]
Balance at end of period	$ 13,211,000		$ 8,087,000		$ 13,211,000		$ 8,087,000

[1] Includes a release for credit losses of $365,000 and $632,000 recorded in the Consolidated Statements of Income for the quarters ended June 30, 2012 and 2011, respectively, representing the Company's 20% non-reimbursable portion under the loss share agreement.

[2] Includes a (release) provision for credit losses of $(299,000) and $240,000 recorded in the Consolidated Statements of Income for the six months ended June 30, 2012 and 2011, respectively, representing the Company's 20% non-reimbursable portion under the loss share agreement.