Allowance For Loan Losses And Credit Quality (Schedule Of Allowance For Loan Losses For Covered Loans, By Loan Portfolio) (Detail) (USD $)	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	$ 193,761,000	$ 136,100,000
(Reversal of) Provision for loan losses	11,752,000	15,461,000
Write-off on transfers to OREO	(12,997,000)	(7,325,000)
Loans charged off	(17,680,000)	(5,962,000)
Recoveries	1,816,000	5,008,000
Balance, end of period	187,285,000	169,988,000
Allowance on loans individually evaluated for impairment	1,695,000		2,186,000
Loans, net of unearned income Balance, end of period	7,549,227,000		7,194,276,000
Covered Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	118,900,000	73,640,000
(Reversal of) Provision for loan losses	2,182,000	4,409,000
(Decrease) Increase in FDIC loss share receivable	10,633,000	26,706,000
Write-off on transfers to OREO	(12,689,000)	(7,325,000)
Loans charged off	(13,283,000)	(225,000)
Recoveries	19,000	510,000
Balance, end of period	105,762,000	97,715,000
Allowance on loans individually evaluated for impairment
Allowance on loans collectively evaluated for impairment	105,762,000	97,715,000
Loans, net of unearned income Balance, end of period	1,190,147,000	1,462,677,000
Balance, end of period: Loans individually evaluated for impairment
Balance, end of period: Loans collectively evaluated for impairment	1,190,147,000	1,462,677,000
Balance, end of period: Loans acquired with deteriorated credit quality	62,196,000	235,205,000
Covered Loans | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	69,175,000	26,439,000
(Reversal of) Provision for loan losses	2,821,000	4,697,000
(Decrease) Increase in FDIC loss share receivable	11,238,000	33,849,000
Write-off on transfers to OREO	(8,545,000)	(4,576,000)
Loans charged off	(13,143,000)	(164,000)
Recoveries	16,000	275,000
Balance, end of period	61,562,000	60,520,000
Allowance on loans individually evaluated for impairment
Allowance on loans collectively evaluated for impairment	61,562,000	60,520,000
Loans, net of unearned income Balance, end of period	653,354,000	805,764,000
Balance, end of period: Loans individually evaluated for impairment
Balance, end of period: Loans collectively evaluated for impairment	653,354,000	805,764,000
Balance, end of period: Loans acquired with deteriorated credit quality	4,789,000	132,798,000
Covered Loans | Commercial Business [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	9,788,000	6,657,000
(Reversal of) Provision for loan losses	848,000	400,000
(Decrease) Increase in FDIC loss share receivable	1,097,000	2,630,000
Write-off on transfers to OREO	(119,000)	(54,000)
Balance, end of period	11,614,000	9,633,000
Allowance on loans individually evaluated for impairment
Allowance on loans collectively evaluated for impairment	11,614,000	9,633,000
Loans, net of unearned income Balance, end of period	125,681,000	158,460,000
Balance, end of period: Loans individually evaluated for impairment
Balance, end of period: Loans collectively evaluated for impairment	125,681,000	158,460,000
Balance, end of period: Loans acquired with deteriorated credit quality	2,483,000	4,162,000
Covered Loans | Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	18,753,000	12,201,000
(Reversal of) Provision for loan losses	62,000	696,000
(Decrease) Increase in FDIC loss share receivable	(3,056,000)	2,543,000
Write-off on transfers to OREO	(825,000)	(1,483,000)
Loans charged off	(9,000)	(41,000)
Recoveries	3,000	133,000
Balance, end of period	14,928,000	14,049,000
Allowance on loans individually evaluated for impairment
Allowance on loans collectively evaluated for impairment	14,928,000	14,049,000
Loans, net of unearned income Balance, end of period	227,544,000	264,136,000
Balance, end of period: Loans individually evaluated for impairment
Balance, end of period: Loans collectively evaluated for impairment	227,544,000	264,136,000
Balance, end of period: Loans acquired with deteriorated credit quality	24,835,000	50,176,000
Covered Loans | Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	21,184,000	28,343,000
(Reversal of) Provision for loan losses	(1,549,000)	(1,384,000)
(Decrease) Increase in FDIC loss share receivable	1,354,000	(12,316,000)
Write-off on transfers to OREO	(3,200,000)	(1,212,000)
Loans charged off	(131,000)	(20,000)
Recoveries		102,000
Balance, end of period	17,658,000	13,513,000
Allowance on loans individually evaluated for impairment
Allowance on loans collectively evaluated for impairment	17,658,000	13,513,000
Loans, net of unearned income Balance, end of period	183,568,000	234,417,000
Balance, end of period: Loans individually evaluated for impairment
Balance, end of period: Loans collectively evaluated for impairment	183,568,000	234,417,000
Balance, end of period: Loans acquired with deteriorated credit quality	30,089,000	48,069,000
Covered Loans | Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance on loans individually evaluated for impairment
Balance, end of period: Loans individually evaluated for impairment