Loans and Leases (Aging Of The Outstanding Loans and Leases By Class Excluding Loans Impaired At Acquisition Date) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012		Mar. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	$ 11,509,080	[1]	$ 11,576,115	[2]	$ 11,489,529	[1]
Commercial Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	8,022,186		7,994,495		7,830,041
Commercial Mortgage | Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	300,497		309,190		346,557
Commercial Mortgage | Other Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	176,456		160,980		150,316
Commercial Mortgage | Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	1,662,124		1,726,126		1,739,724
Commercial Mortgage | Lease Financing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	336,329		330,679		315,704
Commercial Mortgage | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	194,186		125,681		149,792
Non-Commercial Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	3,486,894		3,581,620		3,659,488
Non-Commercial Loans | Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	115,628		131,992		132,677
Non-Commercial Loans | Residential Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	834,879		822,889		793,612
Non-Commercial Loans | Revolving Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	2,150,800		2,210,133		2,282,138
Non-Commercial Loans | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	385,587		416,606		451,061
Noncovered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	64,738		64,528		56,153
60-89 Days Past Due	21,245		19,620		14,560
90 Days or Greater	40,576		50,412		40,906
Total Past Due	126,559		134,560		111,619
Current	11,382,521		11,441,555		11,377,910
Total Loans and Leases	11,509,080		11,576,115		11,489,529
Noncovered Loans | Commercial Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	42,494		45,380		48,434
Current	5,310,100		5,296,459		5,079,514
Total Loans and Leases	5,352,594		5,341,839		5,127,948
Noncovered Loans | Lease Financing
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	635		991		824
60-89 Days Past Due	230		138		99
90 Days or Greater	621		621		1,269
Total Past Due	1,486		1,750		2,192
Current	334,843		328,929		313,512
Total Loans and Leases	336,329		330,679		315,704
Noncovered Loans | Commercial Mortgage | Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	782		927		2,030
60-89 Days Past Due	7,943		0		1,366
90 Days or Greater	1,082		7,878		3,288
Total Past Due	9,807		8,805		6,684
Current	290,690		300,385		339,873
Total Loans and Leases	300,497		309,190		346,557
Noncovered Loans | Commercial Mortgage | Commercial Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	19,321		21,075		27,947
60-89 Days Past Due	5,873		3,987		6,548
90 Days or Greater	17,300		20,318		13,939
Noncovered Loans | Commercial Mortgage | Other Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	346		387		787
60-89 Days Past Due	503		1,240		43
90 Days or Greater	1,282		1,034		193
Total Past Due	2,131		2,661		1,023
Current	174,325		158,319		149,293
Total Loans and Leases	176,456		160,980		150,316
Noncovered Loans | Commercial Mortgage | Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	7,895		6,205		5,522
60-89 Days Past Due	1,878		1,288		1,006
90 Days or Greater	2,406		1,614		1,754
Total Past Due	12,179		9,107		8,282
Current	1,649,945		1,717,019		1,731,442
Total Loans and Leases	1,662,124		1,726,126		1,739,724
Noncovered Loans | Commercial Mortgage | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	42		18		0
60-89 Days Past Due	0		13		0
90 Days or Greater	0		0		0
Total Past Due	42		31		0
Current	194,144		125,650		149,792
Total Loans and Leases	194,186		125,681		149,792
Noncovered Loans | Non-Commercial Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	3,486,894		3,581,620		3,659,488
Noncovered Loans | Non-Commercial Loans | Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	217		1,941		808
60-89 Days Past Due	63		490		446
90 Days or Greater	1,271		797		862
Total Past Due	1,551		3,228		2,116
Current	114,077		128,764		130,561
Total Loans and Leases	115,628		131,992		132,677
Noncovered Loans | Non-Commercial Loans | Residential Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	19,663		15,711		14,001
60-89 Days Past Due	789		7,559		2,812
90 Days or Greater	11,988		12,993		13,388
Total Past Due	32,440		36,263		30,201
Current	802,439		786,626		763,411
Total Loans and Leases	834,879		822,889		793,612
Noncovered Loans | Non-Commercial Loans | Revolving Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	14,022		12,868		2,349
60-89 Days Past Due	2,998		3,200		1,212
90 Days or Greater	3,591		3,879		4,486
Total Past Due	20,611		19,947		8,047
Current	2,130,189		2,190,186		2,274,091
Total Loans and Leases	2,150,800		2,210,133		2,282,138
Noncovered Loans | Non-Commercial Loans | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	1,815		4,405		1,885
60-89 Days Past Due	968		1,705		1,028
90 Days or Greater	1,035		1,278		1,727
Total Past Due	3,818		7,388		4,640
Current	381,769		409,218		446,421
Total Loans and Leases	$ 385,587		$ 416,606		$ 451,061

[1] Unaudited

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