Allowance For Loan Losses And Credit Quality (Schedule Of Allowance For Loan Losses For Non-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
Non-Covered Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	74,861,000	62,460,000
(Reversal of) Provision for loan losses	9,570,000	11,052,000
Write-off on transfers to OREO	(308,000)
Loans charged off	(4,397,000)	(5,737,000)
Recoveries	1,797,000	4,498,000
Balance, end of period	81,523,000	72,273,000
Allowance on loans individually evaluated for impairment	1,695,000	1,838,000
Allowance on loans collectively evaluated for impairment	79,828,000	70,435,000
Loans, net of unearned income Balance, end of period	6,546,365,000	5,737,969,000
Balance, end of period: Loans individually evaluated for impairment	33,081,000	41,291,000
Balance, end of period: Loans collectively evaluated for impairment	6,513,284,000	5,696,678,000
Balance, end of period: Loans acquired with deteriorated credit quality	40,181,000	46,128,000
Non-Covered Loans | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	35,604,000	31,390,000
(Reversal of) Provision for loan losses	2,320,000	2,377,000
Write-off on transfers to OREO	(76,000)
Loans charged off	(1,154,000)	(1,357,000)
Recoveries	654,000	3,218,000
Balance, end of period	37,348,000	35,628,000
Allowance on loans individually evaluated for impairment	1,307,000	1,760,000
Allowance on loans collectively evaluated for impairment	36,041,000	33,508,000
Loans, net of unearned income Balance, end of period	2,660,509,000	2,593,066,000
Balance, end of period: Loans individually evaluated for impairment	28,841,000	36,703,000
Balance, end of period: Loans collectively evaluated for impairment	2,631,668,000	2,556,363,000
Balance, end of period: Loans acquired with deteriorated credit quality	34,650,000	37,464,000
Non-Covered Loans | Commercial Business [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	25,705,000	16,473,000
(Reversal of) Provision for loan losses	4,576,000	4,117,000
Loans charged off	(435,000)	(523,000)
Recoveries	61,000	129,000
Balance, end of period	29,907,000	20,196,000
Allowance on loans individually evaluated for impairment	201,000	47,000
Allowance on loans collectively evaluated for impairment	29,706,000	20,149,000
Loans, net of unearned income Balance, end of period	2,180,479,000	1,604,259,000
Balance, end of period: Loans individually evaluated for impairment	2,402,000	3,648,000
Balance, end of period: Loans collectively evaluated for impairment	2,178,077,000	1,600,611,000
Balance, end of period: Loans acquired with deteriorated credit quality	560,000	500,000
Non-Covered Loans | Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	12,655,000	13,332,000
(Reversal of) Provision for loan losses	1,962,000	4,578,000
Write-off on transfers to OREO	(6,000)
Loans charged off	(2,562,000)	(3,737,000)
Recoveries	1,061,000	1,104,000
Balance, end of period	13,110,000	15,277,000
Allowance on loans collectively evaluated for impairment	13,110,000	15,277,000
Loans, net of unearned income Balance, end of period	1,470,156,000	1,210,928,000
Balance, end of period: Loans individually evaluated for impairment	226,000	237,000
Balance, end of period: Loans collectively evaluated for impairment	1,469,930,000	1,210,691,000
Balance, end of period: Loans acquired with deteriorated credit quality	4,971,000	8,164,000
Non-Covered Loans | Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance, beginning of period	897,000	1,265,000
(Reversal of) Provision for loan losses	712,000	(20,000)
Write-off on transfers to OREO	(226,000)
Loans charged off	(246,000)	(120,000)
Recoveries	21,000	47,000
Balance, end of period	1,158,000	1,172,000
Allowance on loans individually evaluated for impairment	187,000	31,000
Allowance on loans collectively evaluated for impairment	971,000	1,141,000
Loans, net of unearned income Balance, end of period	235,221,000	329,716,000
Balance, end of period: Loans individually evaluated for impairment	1,612,000	703,000
Balance, end of period: Loans collectively evaluated for impairment	$ 233,609,000	$ 329,013,000