Allowance for Loan and Lease Losses (Summary of Activity In Allowance for Loan and Lease Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Dec. 31, 2012		Jun. 30, 2012
Loans and Leases Evaluated for Impairment [Abstract]
Net loans and leases	$ 12,857,388	[1]	$ 13,400,898	[1]	$ 13,066,332	[2]
Loan and Lease Acquired with Deteriorated Credit Quality [Abstract]
Allowance for loan and lease losses	273,019	[1]	272,500	[1]	319,018	[2]
Noncovered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	179,046		180,883				179,046
Charge-offs	(8,067)		(17,632)
Recoveries	1,551		2,020
Provisions	4,016		21,112
Ending balance	176,546		186,383				179,046
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment	15,515		11,349		18,355
ALLL for loans and leases collectively evaluated for impairment	145,259		160,212		144,841
Non-specific ALLL	15,772		14,822		15,850
Total allowance for loan and lease losses	176,546		186,383				179,046
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment	199,215		154,275		202,253
Loans and leases collectively evaluated for impairment	11,309,865		11,335,254		11,373,862
Net loans and leases	11,509,080		11,489,529		11,576,115
Covered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	139,972		89,261
Charge-offs	(20,877)		(12,747)
Recoveries	0		0
Provisions	(22,622)		9,603
Ending balance	96,473		86,117
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
Total allowance for loan and lease losses	96,473		86,117
Loan and Lease Acquired with Deteriorated Credit Quality [Abstract]
ALLL for loans and leases acquired with deteriorated credit quality	96,473		86,117		139,972
Loans and leases acquired with deteriorated credit quality	1,621,327		2,183,869		1,809,235
Construction and Land Development - Commercial | Noncovered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	6,031		5,467				6,031
Charge-offs	(254)		(5,729)
Recoveries	368		42
Provisions	(1,834)		6,828
Ending balance	4,311		6,608				6,031
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment	588		2,605		2,469
ALLL for loans and leases collectively evaluated for impairment	3,723		4,003		3,562
Non-specific ALLL	0		0		0
Total allowance for loan and lease losses	4,311		6,608				6,031
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment	10,353		21,621		17,075
Loans and leases collectively evaluated for impairment	290,144		324,936		292,115
Net loans and leases	300,497		346,557		309,190
Construction and Land Development - Commercial | Covered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	31,186		16,693
Charge-offs	(4,733)		(1,387)
Recoveries	0		0
Provisions	(13,147)		(2,570)
Ending balance	13,306		12,736
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
Total allowance for loan and lease losses	13,306		12,736
Loan and Lease Acquired with Deteriorated Credit Quality [Abstract]
ALLL for loans and leases acquired with deteriorated credit quality	13,306		12,736		31,186
Loans and leases acquired with deteriorated credit quality	204,524		310,601		237,906
Commercial Mortgage | Noncovered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	70,927		67,486				70,927
Charge-offs	(654)		(2,464)
Recoveries	8		996
Provisions	2,536		6,137
Ending balance	72,817		72,155				70,927
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment	10,405		6,662		11,697
ALLL for loans and leases collectively evaluated for impairment	62,412		65,493		59,230
Non-specific ALLL	0		0		0
Total allowance for loan and lease losses	72,817		72,155				70,927
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment	134,707		95,265		133,804
Loans and leases collectively evaluated for impairment	5,217,887		5,032,683		5,208,035
Net loans and leases	5,352,594		5,127,948		5,341,839
Commercial Mortgage | Covered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	50,275		39,557
Charge-offs	(9,898)		(6,211)
Recoveries	0		0
Provisions	(2,084)		6,398
Ending balance	38,293		39,744
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
Total allowance for loan and lease losses	38,293		39,744
Loan and Lease Acquired with Deteriorated Credit Quality [Abstract]
ALLL for loans and leases acquired with deteriorated credit quality	38,293		39,744		50,275
Loans and leases acquired with deteriorated credit quality	948,452		1,195,541		1,054,473
Other Commercial Real Estate | Noncovered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	2,059		2,169				2,059
Charge-offs	(54)		(142)
Recoveries	10		0
Provisions	(100)		221
Ending balance	1,915		2,248				2,059
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment	141		256		298
ALLL for loans and leases collectively evaluated for impairment	1,774		1,992		1,761
Non-specific ALLL	0		0		0
Total allowance for loan and lease losses	1,915		2,248				2,059
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment	3,413		2,721		3,375
Loans and leases collectively evaluated for impairment	173,043		147,595		157,605
Net loans and leases	176,456		150,316		160,980
Other Commercial Real Estate | Covered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	11,234		16,862
Charge-offs	(931)		0
Recoveries	0		0
Provisions	(5,131)		(5,712)
Ending balance	5,172		11,150
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
Total allowance for loan and lease losses	5,172		11,150
Loan and Lease Acquired with Deteriorated Credit Quality [Abstract]
ALLL for loans and leases acquired with deteriorated credit quality	5,172		11,150		11,234
Loans and leases acquired with deteriorated credit quality	93,232		144,978		107,119
Commercial and Industrial | Noncovered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	23,352		23,723				23,352
Charge-offs	(1,258)		(1,447)
Recoveries	369		250
Provisions	500		1,720
Ending balance	22,963		24,246				23,352
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment	3,159		838		2,133
ALLL for loans and leases collectively evaluated for impairment	19,804		23,408		21,219
Non-specific ALLL	0		0		0
Total allowance for loan and lease losses	22,963		24,246				23,352
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment	22,601		17,261		22,619
Loans and leases collectively evaluated for impairment	1,639,523		1,722,463		1,703,507
Net loans and leases	1,662,124		1,739,724		1,726,126
Commercial and Industrial | Covered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	8,897		5,500
Charge-offs	(1,254)		(3,189)
Recoveries	0		0
Provisions	4,233		11,417
Ending balance	11,876		13,728
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
Total allowance for loan and lease losses	11,876		13,728
Loan and Lease Acquired with Deteriorated Credit Quality [Abstract]
ALLL for loans and leases acquired with deteriorated credit quality	11,876		13,728		8,897
Loans and leases acquired with deteriorated credit quality	45,693		93,261		49,463
Lease Financing | Noncovered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,521		3,288				3,521
Charge-offs	0		(191)
Recoveries	0		31
Provisions	22		192
Ending balance	3,543		3,320				3,521
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment	223		19		202
ALLL for loans and leases collectively evaluated for impairment	3,320		3,301		3,319
Non-specific ALLL	0		0		0
Total allowance for loan and lease losses	3,543		3,320				3,521
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment	401		375		804
Loans and leases collectively evaluated for impairment	335,928		315,329		329,875
Net loans and leases	336,329		315,704		330,679
Lease Financing | Covered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	0		13
Charge-offs	0		0
Recoveries	0		0
Provisions	0		(10)
Ending balance	0		3
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
Total allowance for loan and lease losses	0		3
Loan and Lease Acquired with Deteriorated Credit Quality [Abstract]
ALLL for loans and leases acquired with deteriorated credit quality	0		3		0
Loans and leases acquired with deteriorated credit quality	0		45		0
Other | Noncovered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,175		1,315				1,175
Charge-offs	0		0
Recoveries	0		4
Provisions	315		(38)
Ending balance	1,490		1,281				1,175
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment	0		0		53
ALLL for loans and leases collectively evaluated for impairment	1,490		1,281		1,122
Non-specific ALLL	0		0		0
Total allowance for loan and lease losses	1,490		1,281				1,175
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment	0		0		707
Loans and leases collectively evaluated for impairment	194,186		149,792		124,974
Net loans and leases	194,186		149,792		125,681
Residential Mortgage | Noncovered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,836		8,879				3,836
Charge-offs	(818)		(1,035)
Recoveries	39		42
Provisions	733		1,221
Ending balance	3,790		9,107				3,836
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment	694		782		959
ALLL for loans and leases collectively evaluated for impairment	3,096		8,325		2,877
Non-specific ALLL	0		0		0
Total allowance for loan and lease losses	3,790		9,107				3,836
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment	19,720		12,772		15,836
Loans and leases collectively evaluated for impairment	815,159		780,840		807,053
Net loans and leases	834,879		793,612		822,889
Residential Mortgage | Covered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	19,837		5,433
Charge-offs	(729)		(1,955)
Recoveries	0		0
Provisions	(1,505)		1,254
Ending balance	17,603		4,732
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
Total allowance for loan and lease losses	17,603		4,732
Loan and Lease Acquired with Deteriorated Credit Quality [Abstract]
ALLL for loans and leases acquired with deteriorated credit quality	17,603		4,732		19,837
Loans and leases acquired with deteriorated credit quality	278,997		298,538		297,926
Revolving Mortgage | Noncovered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	25,185		27,045				25,185
Charge-offs	(2,188)		(2,940)
Recoveries	71		216
Provisions	1,431		2,590
Ending balance	24,499		26,911				25,185
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment	44		0		1
ALLL for loans and leases collectively evaluated for impairment	24,455		26,911		25,184
Non-specific ALLL	0		0		0
Total allowance for loan and lease losses	24,499		26,911				25,185
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment	5,471		0		4,203
Loans and leases collectively evaluated for impairment	2,145,329		2,282,138		2,205,930
Net loans and leases	2,150,800		2,282,138		2,210,133
Revolving Mortgage | Covered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	9,754		77
Charge-offs	(114)		0
Recoveries	0		0
Provisions	(2,505)		950
Ending balance	7,135		1,027
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
Total allowance for loan and lease losses	7,135		1,027
Loan and Lease Acquired with Deteriorated Credit Quality [Abstract]
ALLL for loans and leases acquired with deteriorated credit quality	7,135		1,027		9,754
Loans and leases acquired with deteriorated credit quality	37,139		50,016		38,710
Construction and Land Development - Non - Commercial | Noncovered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,721		1,427				1,721
Charge-offs	(245)		(676)
Recoveries	56		7
Provisions	(113)		639
Ending balance	1,419		1,397				1,721
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment	82		145		287
ALLL for loans and leases collectively evaluated for impairment	1,337		1,252		1,434
Non-specific ALLL	0		0		0
Total allowance for loan and lease losses	1,419		1,397				1,721
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment	866		3,345		1,321
Loans and leases collectively evaluated for impairment	114,762		129,332		130,671
Net loans and leases	115,628		132,677		131,992
Construction and Land Development - Non - Commercial | Covered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	8,287		4,652
Charge-offs	(3,218)		0
Recoveries	0		0
Provisions	(2,313)		(1,932)
Ending balance	2,756		2,720
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
Total allowance for loan and lease losses	2,756		2,720
Loan and Lease Acquired with Deteriorated Credit Quality [Abstract]
ALLL for loans and leases acquired with deteriorated credit quality	2,756		2,720		8,287
Loans and leases acquired with deteriorated credit quality	11,024		85,555		20,793
Consumer | Noncovered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	25,389		25,962				25,389
Charge-offs	(2,596)		(3,008)
Recoveries	630		432
Provisions	604		902
Ending balance	24,027		24,288				25,389
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment	179		42		256
ALLL for loans and leases collectively evaluated for impairment	23,848		24,246		25,133
Non-specific ALLL	0		0		0
Total allowance for loan and lease losses	24,027		24,288				25,389
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment	1,683		915		2,509
Loans and leases collectively evaluated for impairment	383,904		450,146		414,097
Net loans and leases	385,587		451,061		416,606
Consumer | Covered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	502		474
Charge-offs	0		(5)
Recoveries	0		0
Provisions	(170)		(192)
Ending balance	332		277
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
Total allowance for loan and lease losses	332		277
Loan and Lease Acquired with Deteriorated Credit Quality [Abstract]
ALLL for loans and leases acquired with deteriorated credit quality	332		277		502
Loans and leases acquired with deteriorated credit quality	2,266		5,334		2,845
Non-Specific | Noncovered Loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	15,850		14,122				15,850
Charge-offs	0		0
Recoveries	0		0
Provisions	(78)		700
Ending balance	15,772		14,822				15,850
Allowance for Loans and Leases Evaluated for Impairment [Abstract]
ALLL for loans and leases individually evaluated for impairment	0		0		0
ALLL for loans and leases collectively evaluated for impairment	0		0		0
Non-specific ALLL	15,772		14,822		15,850
Total allowance for loan and lease losses	15,772		14,822				15,850
Loans and Leases Evaluated for Impairment [Abstract]
Loans and leases individually evaluated for impairment	0		0		0
Loans and leases collectively evaluated for impairment	0		0		0
Net loans and leases	$ 0		$ 0		$ 0

[1] Unaudited

[2] Derived from 2012 Annual Report on Form 10-K.