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	Jun. 30, 2012		Dec. 31, 2011		Jun. 30, 2011
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	$ 11,462,458	[1]	$ 11,581,637	[2]	$ 11,528,854	[1]
Commercial Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	7,825,628		7,866,572		7,697,242
Commercial Mortgage | Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	329,151		381,163		407,134
Commercial Mortgage | Commercial Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	1,722,761		1,764,407		1,805,812
Commercial Mortgage | Other Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	162,579		144,771		148,977
Commercial Mortgage | Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	1,722,761		1,764,407		1,805,812
Commercial Mortgage | Lease Financing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	320,703		312,869		303,104
Commercial Mortgage | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	140,738		158,369		170,758
Non-Commercial Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	3,636,830		3,715,065		3,831,612
Non-Commercial Loans | Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	127,726		137,271		145,445
Non-Commercial Loans | Residential Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	809,230		784,118		825,610
Non-Commercial Loans | Revolving Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	2,268,210		2,296,306		2,303,687
Non-Commercial Loans | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	431,664		497,370		556,870
Noncovered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	46,554		46,999		27,460
60-89 Days Past Due	14,129		13,647		14,265
90 Days or Greater	46,562		39,282		50,235
Total Past Due	107,245		99,928		91,960
Current	11,355,213		11,481,709		11,436,894
Total Loans and Leases	11,462,458		11,581,637		11,528,854
Noncovered Loans | Commercial Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	15,830		18,308		12,985
60-89 Days Past Due	5,171		4,438		5,580
90 Days or Greater	16,832		15,626		21,467
Total Past Due	37,833		38,372		40,032
Current	5,111,863		5,066,621		4,821,425
Total Loans and Leases	5,149,696		5,104,993		4,861,457
Noncovered Loans | Other Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	284		657		270
60-89 Days Past Due	68		147		54
90 Days or Greater	551		561		586
Total Past Due	903		1,365		910
Current	161,676		143,406		148,067
Total Loans and Leases	162,579		144,771		148,977
Noncovered Loans | Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	2,528		5,235		3,102
60-89 Days Past Due	882		1,230		909
90 Days or Greater	2,153		1,438		2,402
Total Past Due	5,563		7,903		6,413
Current	1,717,198		1,756,504		1,799,399
Total Loans and Leases	1,722,761		1,764,407		1,805,812
Noncovered Loans | Lease Financing
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	305		637		337
60-89 Days Past Due	4		212		82
90 Days or Greater	530		620		359
Total Past Due	839		1,469		778
Current	319,864		311,400		302,326
Total Loans and Leases	320,703		312,869		303,104
Noncovered Loans | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	100		0		0
60-89 Days Past Due	0		0		0
90 Days or Greater	0		0		0
Total Past Due	100		0		0
Current	140,638		158,369		170,758
Total Loans and Leases	140,738		158,369		170,758
Noncovered Loans | Residential Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	12,601		11,790		3,376
60-89 Days Past Due	3,659		2,686		2,897
90 Days or Greater	11,338		12,529		12,898
Total Past Due	27,598		27,005		19,171
Current	781,632		757,113		806,439
Total Loans and Leases	809,230		784,118		825,610
Noncovered Loans | Revolving Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	10,131		3,437		3,500
60-89 Days Past Due	2,460		2,042		1,732
90 Days or Greater	4,191		4,316		7,302
Total Past Due	16,782		9,795		12,534
Current	2,251,428		2,286,511		2,291,153
Total Loans and Leases	2,268,210		2,296,306		2,303,687
Noncovered Loans | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	1,993		3,514		2,633
60-89 Days Past Due	975		1,271		1,128
90 Days or Greater	1,473		1,443		1,503
Total Past Due	4,441		6,228		5,264
Current	427,223		491,142		551,606
Total Loans and Leases	431,664		497,370		556,870
Noncovered Loans | Commercial Mortgage | Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	1,430		2,623		876
60-89 Days Past Due	463		1,494		763
90 Days or Greater	8,663		2,177		3,150
Total Past Due	10,556		6,294		4,789
Current	318,595		374,869		402,345
Total Loans and Leases	329,151		381,163		407,134
Noncovered Loans | Non-Commercial Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	3,636,830		3,715,065		3,831,612
Noncovered Loans | Non-Commercial Loans | Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	1,352		798		381
60-89 Days Past Due	447		127		1,120
90 Days or Greater	831		572		568
Total Past Due	2,630		1,497		2,069
Current	125,096		135,774		143,376
Total Loans and Leases	127,726		137,271		145,445
Noncovered Loans | Non-Commercial Loans | Residential Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	809,230		784,118		825,610
Noncovered Loans | Non-Commercial Loans | Revolving Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	2,268,210		2,296,306		2,303,687
Noncovered Loans | Non-Commercial Loans | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	$ 431,664		$ 497,370		$ 556,870

[1] Unaudited

[2] Derived from 2011 Annual Report on Form 10-K.