Loans and Leases (Loans Acquired By Loan Class) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012		Jun. 30, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	$ 1,443,336	[1]	$ 1,809,235	[2]	$ 1,999,351	[1]
Commercial Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	1,140,029		1,450,035		1,598,579
Commercial Mortgage | Construction and Land Development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	160,733		237,906		272,445
Commercial Mortgage | Commercial Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	859,038		1,054,473		1,142,677
Commercial Mortgage | Other Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	81,904		107,119		115,787
Commercial Mortgage | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	37,336		49,463		66,442
Commercial Mortgage | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	1,018		1,074		1,228
Non-Commercial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	303,307		359,200		400,772
Non-Commercial Loans | Construction and Land Development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	9,009		20,793		39,294
Non-Commercial Loans | Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	256,972		297,926		322,053
Non-Commercial Loans | Revolving Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	36,153		38,710		37,110
Non-Commercial Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	1,173		1,771		2,315
Impaired At Acquisition Date
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	217,476		290,626		337,648
Impaired At Acquisition Date | Commercial Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	162,627		217,807		241,606
Impaired At Acquisition Date | Commercial Mortgage | Construction and Land Development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	41,572		71,225		86,056
Impaired At Acquisition Date | Commercial Mortgage | Commercial Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	90,910		107,281		121,580
Impaired At Acquisition Date | Commercial Mortgage | Other Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	23,716		35,369		29,199
Impaired At Acquisition Date | Commercial Mortgage | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	6,429		3,932		4,771
Impaired At Acquisition Date | Commercial Mortgage | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	0		0		0
Impaired At Acquisition Date | Non-Commercial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	54,849		72,819		96,042
Impaired At Acquisition Date | Non-Commercial Loans | Construction and Land Development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	8,616		15,136		31,767
Impaired At Acquisition Date | Non-Commercial Loans | Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	36,740		48,077		55,585
Impaired At Acquisition Date | Non-Commercial Loans | Revolving Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	9,493		9,606		8,286
Impaired At Acquisition Date | Non-Commercial Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	0		0		404
All Other Acquired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	1,225,860		1,518,609		1,661,703
All Other Acquired Loans | Commercial Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	977,402		1,232,228		1,356,973
All Other Acquired Loans | Commercial Mortgage | Construction and Land Development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	119,161		166,681		186,389
All Other Acquired Loans | Commercial Mortgage | Commercial Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	768,128		947,192		1,021,097
All Other Acquired Loans | Commercial Mortgage | Other Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	58,188		71,750		86,588
All Other Acquired Loans | Commercial Mortgage | Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	30,907		45,531		61,671
All Other Acquired Loans | Commercial Mortgage | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	1,018		1,074		1,228
All Other Acquired Loans | Non-Commercial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	248,458		286,381		304,730
All Other Acquired Loans | Non-Commercial Loans | Construction and Land Development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	393		5,657		7,527
All Other Acquired Loans | Non-Commercial Loans | Residential Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	220,232		249,849		266,468
All Other Acquired Loans | Non-Commercial Loans | Revolving Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	26,660		29,104		28,824
All Other Acquired Loans | Non-Commercial Loans | Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired	$ 1,173		$ 1,771		$ 1,911

[1] Unaudited

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