Loans and Allowance for Credit Losses Past Due Loan Status and Non-Accrual Loans by Portfolio Segment (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	$ 63,180	$ 51,177
60-89 Days Past Due	18,109	17,169
>90 Days Past Due and Accruing	19,365	17,402
Non-accrual	129,929	121,080
Total >90 Days	149,294	138,482
Total Past Due	230,583	206,828
Current	12,884,922	12,904,888
Loans, net of unearned income	13,115,505	13,111,716	12,733,792
Real-estate commercial mortage [Member]
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	20,528	14,399
60-89 Days Past Due	5,620	3,677
>90 Days Past Due and Accruing	40	800
Non-accrual	46,291	44,437
Total >90 Days	46,331	45,237
Total Past Due	72,479	63,313
Current	5,154,622	5,133,842
Loans, net of unearned income	5,227,101	5,197,155	5,137,454
Commercial - industrial, financial, and agricultural [Member]
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	8,888	5,234
60-89 Days Past Due	1,060	1,023
>90 Days Past Due and Accruing	3,646	619
Non-accrual	39,619	29,769
Total >90 Days	43,265	30,388
Total Past Due	53,213	36,645
Current	3,709,418	3,688,922
Loans, net of unearned income	3,762,631	3,725,567	3,574,130
Commercial - Secured [Member]
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	8,056	4,839
60-89 Days Past Due	1,002	958
>90 Days Past Due and Accruing	3,646	610
Non-accrual	38,548	28,747
Total >90 Days	42,194	29,357
Total Past Due	51,252	35,154
Current	3,557,134	3,529,460
Loans, net of unearned income	3,608,386	3,564,614
Commercial - unsecured [Member]
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	832	395
60-89 Days Past Due	58	65
>90 Days Past Due and Accruing	0	9
Non-accrual	1,071	1,022
Total >90 Days	1,071	1,031
Total Past Due	1,961	1,491
Current	152,284	159,462
Loans, net of unearned income	154,245	160,953
Real-estate - construction [Member]
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	1,976	160
60-89 Days Past Due	151	0
>90 Days Past Due and Accruing	146	51
Non-accrual	13,994	16,348
Total >90 Days	14,140	16,399
Total Past Due	16,267	16,559
Current	661,539	674,042
Loans, net of unearned income	677,806	690,601	584,217
Real-estate - home equity [Member]
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	10,347	8,048
60-89 Days Past Due	2,277	2,883
>90 Days Past Due and Accruing	4,785	4,257
Non-accrual	9,670	10,483
Total >90 Days	14,455	14,740
Total Past Due	27,079	25,671
Current	1,674,544	1,711,017
Loans, net of unearned income	1,701,623	1,736,688	1,740,496
Real-estate - residential mortgage [Member]
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	16,375	18,789
60-89 Days Past Due	7,519	8,145
>90 Days Past Due and Accruing	8,242	8,952
Non-accrual	20,353	20,043
Total >90 Days	28,595	28,995
Total Past Due	52,489	55,929
Current	1,312,299	1,321,139
Loans, net of unearned income	1,364,788	1,377,068	1,331,465
Construction - Commercial Residential [Member]
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	1,559	160
60-89 Days Past Due	151	0
>90 Days Past Due and Accruing	98	0
Non-accrual	12,442	13,463
Total >90 Days	12,540	13,463
Total Past Due	14,250	13,623
Current	217,283	190,047
Loans, net of unearned income	231,533	203,670
Construction - Commercial [Member]
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	0	0
60-89 Days Past Due	0	0
>90 Days Past Due and Accruing	0	0
Non-accrual	1,271	2,604
Total >90 Days	1,271	2,604
Total Past Due	1,271	2,604
Current	392,137	424,815
Loans, net of unearned income	393,408	427,419
Construction other [Member]
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	417	0
60-89 Days Past Due	0	0
>90 Days Past Due and Accruing	48	51
Non-accrual	281	281
Total >90 Days	329	332
Total Past Due	746	332
Current	52,119	59,180
Loans, net of unearned income	52,865	59,512
Consumer [Member]
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	3,400	4,190
60-89 Days Past Due	1,172	1,275
>90 Days Past Due and Accruing	2,482	2,590
Non-accrual	2	0
Total >90 Days	2,484	2,590
Total Past Due	7,056	8,055
Current	250,245	257,376
Loans, net of unearned income	257,301	265,431	270,021
Consumer - direct [Member]
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	1,978	2,034
60-89 Days Past Due	941	857
>90 Days Past Due and Accruing	2,390	2,414
Non-accrual	0	0
Total >90 Days	2,390	2,414
Total Past Due	5,309	5,305
Current	97,959	104,018
Loans, net of unearned income	103,268	109,323
Consumer - Indirect [Member]
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	1,422	2,156
60-89 Days Past Due	231	418
>90 Days Past Due and Accruing	92	176
Non-accrual	2	0
Total >90 Days	94	176
Total Past Due	1,747	2,750
Current	152,286	153,358
Loans, net of unearned income	154,033	156,108
Leasing and other and overdrafts [Member]
Financial Receivable, Recorded investment, Past Due [Line Items]
31-59 Days Past Due	1,666	357
60-89 Days Past Due	310	166
>90 Days Past Due and Accruing	24	133
Non-accrual	0	0
Total >90 Days	24	133
Total Past Due	2,000	656
Current	122,255	118,550
Loans, net of unearned income	$ 124,255	$ 119,206	$ 96,009

Financing receivables that are less than 60 days past due but more than 29 days past due.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 7A

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953401-111524

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- Definition

Financing receivables that are less than 90 days past due but more than 59 days past due.

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- Definition

Recorded investment in financing receivables that are 90 days or more past due and still accruing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 7

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5111-111524

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- Definition

Financing receivables that are current.

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- Definition

Financing receivables that are equal to or greater than 90 days past due.

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- Definition

Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

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- Definition

Recorded Investment in financing receivables that are past due at the balance sheet date.

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