Allowance for Loan and Lease Losses (Allocation of Allowance for Loan and Lease Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012	Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification				$ 7,368		$ 0
Allowance for loan and lease losses	237,799	[1]		237,799	[1]		319,018	[2]
Noncommerical
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification				7,368	[3]
Noncommerical | Non-specific
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification				(15,772)	[3]
Originated Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	0	[3]		7,368	[3]
Unpaid principal balance	165,749			165,749			192,238
ALLL for loans and leases individually evaluated for impairment	14,216			14,216			18,355
Financing Receivable, Individually Evaluated for Impairment	155,916			155,916			202,253
Average balance	162,334		166,518	157,018		152,660
Interest income recognized	2,021		2,067	6,112		5,885
Originated Loans | Commercial | Construction and land development
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	0	[3]		5,141	[3]
Unpaid principal balance	7,364			7,364			31,879
ALLL for loans and leases individually evaluated for impairment	435			435			2,469
Financing Receivable, Individually Evaluated for Impairment	2,290			2,290			17,075
Average balance	5,553		24,046	7,793		24,595
Interest income recognized	29		239	242		756
Originated Loans | Commercial | Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	0	[3]		27,421	[3]
Unpaid principal balance	120,254			120,254			123,964
ALLL for loans and leases individually evaluated for impairment	8,506			8,506			11,697
Financing Receivable, Individually Evaluated for Impairment	116,222			116,222			133,804
Average balance	117,584		100,751	107,929		90,544
Interest income recognized	1,575		1,332	4,413		3,621
Originated Loans | Commercial | Other commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	0	[3]		(815)	[3]
Unpaid principal balance	3,131			3,131			3,348
ALLL for loans and leases individually evaluated for impairment	133			133			298
Financing Receivable, Individually Evaluated for Impairment	2,835			2,835			3,375
Average balance	2,852		2,191	2,893		2,502
Interest income recognized	39		33	121		83
Originated Loans | Commercial | Commercial and industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	0	[3]		7,551	[3]
Unpaid principal balance	11,512			11,512			9,583
ALLL for loans and leases individually evaluated for impairment	2,500			2,500			2,133
Financing Receivable, Individually Evaluated for Impairment	11,282			11,282			22,619
Average balance	12,136		13,414	13,811		11,847
Interest income recognized	127		186	533		682
Originated Loans | Commercial | Lease financing
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	0	[3]		(253)	[3]
Unpaid principal balance	309			309			746
ALLL for loans and leases individually evaluated for impairment	177			177			202
Financing Receivable, Individually Evaluated for Impairment	309			309			804
Average balance	312		689	399		412
Interest income recognized	5		11	19		22
Originated Loans | Commercial | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	0	[3]		(1,288)	[3]
Unpaid principal balance	0			0			707
ALLL for loans and leases individually evaluated for impairment	0			0			53
Financing Receivable, Individually Evaluated for Impairment	0			0			707
Average balance	0		734	0		327
Interest income recognized	0		0	0		0
Originated Loans | Noncommerical | Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	0	[3]		5,717	[3]
Unpaid principal balance	14,534			14,534			13,978
ALLL for loans and leases individually evaluated for impairment	1,113			1,113			959
Financing Receivable, Individually Evaluated for Impairment	14,333			14,333			15,836
Average balance	15,137		16,111	15,441		15,278
Interest income recognized	181		206	253		536
Originated Loans | Noncommerical | Construction and land development
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	0	[3]		(478)	[3]
Unpaid principal balance	938			938			1,321
ALLL for loans and leases individually evaluated for impairment	52			52			287
Financing Receivable, Individually Evaluated for Impairment	938			938			1,321
Average balance	943		3,012	907		3,017
Interest income recognized	14		33	39		122
Originated Loans | Noncommerical | Revolving mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	0	[3]		(9,838)	[3]
Unpaid principal balance	6,495			6,495			4,203
ALLL for loans and leases individually evaluated for impairment	1,167			1,167			1
Financing Receivable, Individually Evaluated for Impairment	6,495			6,495			4,203
Average balance	6,564		3,592	6,337		2,507
Interest income recognized	47		20	459		40
Originated Loans | Noncommerical | Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	0	[3]		(10,018)	[3]
Unpaid principal balance	1,212			1,212			2,509
ALLL for loans and leases individually evaluated for impairment	133			133			256
Financing Receivable, Individually Evaluated for Impairment	1,212			1,212			2,509
Average balance	1,253		1,978	1,508		1,631
Interest income recognized	4		7	33		23
Originated Loans | Noncommerical | Non-specific
Financing Receivable, Allowance for Credit Losses [Line Items]
Reclassification	0	[3]		(15,772)	[3]
Unpaid principal balance	0			0			0
ALLL for loans and leases individually evaluated for impairment	0			0			0
Financing Receivable, Individually Evaluated for Impairment	0			0			0
Originated Loans | With A Recorded Allowance
Financing Receivable, Allowance for Credit Losses [Line Items]
Total impaired noncovered loans and leases	104,427			104,427			97,785
Originated Loans | With A Recorded Allowance | Commercial | Construction and land development
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	1,941			1,941			6,960
Originated Loans | With A Recorded Allowance | Commercial | Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	71,829			71,829			61,644
Originated Loans | With A Recorded Allowance | Commercial | Other commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	1,210			1,210			1,552
Originated Loans | With A Recorded Allowance | Commercial | Commercial and industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	10,911			10,911			11,248
Originated Loans | With A Recorded Allowance | Commercial | Lease financing
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	309			309			723
Originated Loans | With A Recorded Allowance | Commercial | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	0			0			53
Originated Loans | With A Recorded Allowance | Noncommerical | Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	11,652			11,652			11,596
Originated Loans | With A Recorded Allowance | Noncommerical | Construction and land development
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	475			475			1,162
Originated Loans | With A Recorded Allowance | Noncommerical | Revolving mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	4,888			4,888			1,238
Originated Loans | With A Recorded Allowance | Noncommerical | Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	1,212			1,212			1,609
Originated Loans | With A Recorded Allowance | Noncommerical | Non-specific
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	0			0			0
Originated Loans | With No Recorded Allowance
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	51,489			51,489			104,468
Originated Loans | With No Recorded Allowance | Commercial | Construction and land development
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	349			349			10,115
Originated Loans | With No Recorded Allowance | Commercial | Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	44,393			44,393			72,160
Originated Loans | With No Recorded Allowance | Commercial | Other commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	1,625			1,625			1,823
Originated Loans | With No Recorded Allowance | Commercial | Commercial and industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	371			371			11,371
Originated Loans | With No Recorded Allowance | Commercial | Lease financing
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	0			0			81
Originated Loans | With No Recorded Allowance | Commercial | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	0			0			654
Originated Loans | With No Recorded Allowance | Noncommerical | Mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	2,681			2,681			4,240
Originated Loans | With No Recorded Allowance | Noncommerical | Construction and land development
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	463			463			159
Originated Loans | With No Recorded Allowance | Noncommerical | Revolving mortgage
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	1,607			1,607			2,965
Originated Loans | With No Recorded Allowance | Noncommerical | Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	0			0			900
Originated Loans | With No Recorded Allowance | Noncommerical | Non-specific
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	0			0			0
Acquired Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans which have adverse change in expected cash flows	$ 514,166			$ 514,166

[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.