Allowance for Loan and Lease Losses (Allocation of Allowance for Loan and Lease Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012		Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification					$ 7,368		$ 0
Acquired loans which have adverse change in expected cash flows	631,801				631,801
Total impaired noncovered loans and leases	177,616		191,890		177,616		191,890		172,984
Unpaid principal balance	180,890		213,109		180,890		213,109		192,238
Related allowance recorded	76,534				76,534
Allowance for loan and lease losses	258,316	[1]	272,929	[1]	258,316	[1]	272,929	[1]	319,018	[2]
Average balance	147,704		174,687		153,619		159,720
Interest income recognized	1,968		1,652		4,091		2,193
Construction and Land Development - Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Total impaired noncovered loans and leases	8,921		27,173		8,921		27,173		16,057
Unpaid principal balance	9,921		44,157		9,921		44,157		31,879
Average balance	8,541		26,616		8,899		27,118
Interest income recognized	101		249		213		283
Commercial Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Total impaired noncovered loans and leases	127,628		117,967		127,628		117,967		111,808
Unpaid principal balance	129,522		128,526		129,522		128,526		123,964
Average balance	102,356		106,563		103,032		92,357
Interest income recognized	1,413		1,062		2,838		1,414
Other Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total impaired noncovered loans and leases	2,887		3,709		2,887		3,709		3,248
Unpaid principal balance	2,887		3,871		2,887		3,871		3,348
Average balance	2,647		3,268		3,028		3,140
Interest income recognized	37		48		82		48
Commercial and Industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Total impaired noncovered loans and leases	12,004		13,927		12,004		13,927		18,800
Unpaid principal balance	12,004		7,005		12,004		7,005		9,583
Average balance	10,298		9,644		14,465		14,135
Interest income recognized	139		66		406		120
Lease Financing
Financing Receivable, Allowance for Credit Losses [Line Items]
Total impaired noncovered loans and leases	724		292		724		292		746
Unpaid principal balance	724		292		724		292		746
Average balance	531		343		408		339
Interest income recognized	9		3		14		4
Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Total impaired noncovered loans and leases			742				742		707
Unpaid principal balance			742				742		707
Average balance	0		243		0		124
Interest income recognized	0		13		0		13
Residential Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Total impaired noncovered loans and leases	16,151		17,920		16,151		17,920		13,586
Unpaid principal balance	16,531		18,355		16,531		18,355		13,978
Average balance	13,855		19,607		15,003		15,298
Interest income recognized	184		154		412		234
Revolving Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Total impaired noncovered loans and leases	6,973		3,594		6,973		3,594		4,203
Unpaid principal balance	6,973		3,594		6,973		3,594		4,203
Average balance	6,976		3,917		6,390		1,956
Interest income recognized	47		20		72		20
Construction and Land Development - Noncommercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Total impaired noncovered loans and leases	910		3,458		910		3,458		1,320
Unpaid principal balance	910		3,458		910		3,458		1,321
Average balance	913		2,529		783		3,518
Interest income recognized	13		31		25		50
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Total impaired noncovered loans and leases	1,418		3,108		1,418		3,108		2,509
Unpaid principal balance	1,418		3,109		1,418		3,109		2,509
Average balance	1,587		1,957		1,611		1,735
Interest income recognized	25		6		29		7
With A Recorded Allowance
Financing Receivable, Allowance for Credit Losses [Line Items]
Related allowance recorded	14,581		14,826		14,581		14,826		16,819
With A Recorded Allowance | Construction and Land Development - Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Related allowance recorded	976		1,555		976		1,555		2,340
With A Recorded Allowance | Commercial Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Related allowance recorded	8,687		8,811		8,687		8,811		10,628
With A Recorded Allowance | Other Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Related allowance recorded	115		435		115		435		279
With A Recorded Allowance | Commercial and Industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Related allowance recorded	2,286		2,070		2,286		2,070		1,949
With A Recorded Allowance | Lease Financing
Financing Receivable, Allowance for Credit Losses [Line Items]
Related allowance recorded	376		66		376		66		194
With A Recorded Allowance | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Related allowance recorded			0				0		53
With A Recorded Allowance | Residential Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Related allowance recorded	1,073		1,380		1,073		1,380		832
With A Recorded Allowance | Revolving Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Related allowance recorded	895		51		895		51		1
With A Recorded Allowance | Construction and Land Development - Noncommercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Related allowance recorded	41		205		41		205		287
With A Recorded Allowance | Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Related allowance recorded	132		253		132		253		256
Originated Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	7,368	[3]			7,368	[3]
Originated Loans | Non-Specific
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	(15,772)	[3]			(15,772)	[3]
Originated Loans | Construction and Land Development - Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	5,141	[3]			5,141	[3]
Originated Loans | Commercial Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	27,421	[3]			27,421	[3]
Originated Loans | Other Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	(815)	[3]			(815)	[3]
Originated Loans | Commercial and Industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	7,551	[3]			7,551	[3]
Originated Loans | Lease Financing
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	(253)	[3]			(253)	[3]
Originated Loans | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	(1,288)	[3]			(1,288)	[3]
Originated Loans | Residential Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	5,717	[3]			5,717	[3]
Originated Loans | Construction and Land Development - Noncommercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	(478)	[3]			(478)	[3]
Originated Loans | Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	(10,018)	[3]			(10,018)	[3]
Originated Loans | With A Recorded Allowance
Financing Receivable, Allowance for Credit Losses [Line Items]
Total impaired noncovered loans and leases	104,400		97,691		104,400		97,691		68,463
Originated Loans | With A Recorded Allowance | Construction and Land Development - Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	8,572		8,700		8,572		8,700		5,941
Originated Loans | With A Recorded Allowance | Commercial Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	71,663		64,016		71,663		64,016		39,648
Originated Loans | With A Recorded Allowance | Other Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	1,239		1,218		1,239		1,218		1,425
Originated Loans | With A Recorded Allowance | Commercial and Industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	7,031		5,923		7,031		5,923		7,429
Originated Loans | With A Recorded Allowance | Lease Financing
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	724		292		724		292		665
Originated Loans | With A Recorded Allowance | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses			0				0		0
Originated Loans | With A Recorded Allowance | Residential Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	9,129		13,076		9,129		13,076		9,346
Originated Loans | With A Recorded Allowance | Revolving Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	4,183		1,240		4,183		1,240		1,238
Originated Loans | With A Recorded Allowance | Construction and Land Development - Noncommercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	441		1,311		441		1,311		1,162
Originated Loans | With A Recorded Allowance | Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	1,418		1,915		1,418		1,915		1,609
Originated Loans | With No Recorded Allowance
Financing Receivable, Allowance for Credit Losses [Line Items]
Total impaired noncovered loans and leases	73,216		94,199		73,216		94,199		104,521
Originated Loans | With No Recorded Allowance | Construction and Land Development - Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	349		18,473		349		18,473		10,116
Originated Loans | With No Recorded Allowance | Commercial Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	55,965		53,951		55,965		53,951		72,160
Originated Loans | With No Recorded Allowance | Other Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	1,648		2,491		1,648		2,491		1,823
Originated Loans | With No Recorded Allowance | Commercial and Industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	4,973		8,004		4,973		8,004		11,371
Originated Loans | With No Recorded Allowance | Lease Financing
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	0		0		0		0		81
Originated Loans | With No Recorded Allowance | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses			742				742		707
Originated Loans | With No Recorded Allowance | Residential Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	7,022		4,844		7,022		4,844		4,240
Originated Loans | With No Recorded Allowance | Revolving Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	2,790		2,354		2,790		2,354		2,965
Originated Loans | With No Recorded Allowance | Construction and Land Development - Noncommercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	469		2,147		469		2,147		158
Originated Loans | With No Recorded Allowance | Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	$ 0		$ 1,193		$ 0		$ 1,193		$ 900

[1] Unaudited

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

[3] (1) Reclassification results from enhancements to the ALLL calculation during the second quarter of 2013 that resulted in the allocation of $15,772 previously designated as 'non-specific' to other loan classes and the absorption of $7,368 of the reserve for unfunded commitments related to unfunded, revocable loan commitments into the ALLL. Further discussion is contained in Note A.