Loans and Leases (Aging Of The Outstanding Loans and Leases By Class Excluding Loans Impaired At Acquisition Date) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	$ 20,928,709	$ 19,289,474
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	13,760,703	12,630,489
Commercial | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	649,157	620,352
Commercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	9,026,220	8,274,548
Commercial | Other commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	351,291	321,021
Commercial | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	2,567,501	2,368,958
Commercial | Lease financing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	826,270	730,778
Commercial | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	340,264	314,832
Noncommercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	7,168,006	6,658,985
Noncommercial | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	231,400	220,073
Noncommercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	2,889,124	2,695,985
Noncommercial | Revolving mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	2,601,344	2,523,106
Noncommercial | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	1,446,138	1,219,821
Non-PCI Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	129,252	121,576
Current	20,799,457	19,167,898
Non-PCI Loans	20,928,709	19,289,474
Non-PCI Loans | Commercial | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	2,170	1,733
Current	646,987	618,619
Non-PCI Loans	649,157	620,352
Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	24,694	30,964
Current	9,001,526	8,243,584
Non-PCI Loans	9,026,220	8,274,548
Non-PCI Loans | Commercial | Other commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	310	1,026
Current	350,981	319,995
Non-PCI Loans	351,291	321,021
Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	11,071	4,992
Current	2,556,430	2,363,966
Non-PCI Loans	2,567,501	2,368,958
Non-PCI Loans | Commercial | Lease financing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	2,482	2,236
Current	823,788	728,542
Non-PCI Loans	826,270	730,778
Non-PCI Loans | Commercial | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	270	301
Current	339,994	314,531
Non-PCI Loans	340,264	314,832
Non-PCI Loans | Noncommercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	7,079,751	6,578,661
Non-PCI Loans	7,168,006	6,658,985
Non-PCI Loans | Noncommercial | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	2,294	5,518
Current	229,106	214,555
Non-PCI Loans	231,400	220,073
Non-PCI Loans | Noncommercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	50,079	44,776
Current	2,839,045	2,651,209
Non-PCI Loans	2,889,124	2,695,985
Non-PCI Loans | Noncommercial | Revolving mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	24,402	21,041
Current	2,576,942	2,502,065
Non-PCI Loans	2,601,344	2,523,106
Non-PCI Loans | Noncommercial | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	11,480	8,989
Current	1,434,658	1,210,832
Non-PCI Loans	1,446,138	1,219,821
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	72,876	63,522
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Commercial | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,845	987
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	11,592	13,023
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Commercial | Other commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	310	884
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	7,918	2,133
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Commercial | Lease financing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,175	2,070
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Commercial | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	72	3
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Noncommercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	49,964	44,422
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,139	3,211
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	27,760	23,960
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Revolving mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	14,290	11,706
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	6,775	5,545
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	18,472	18,705
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Commercial | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	39	283
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	2,773	3,446
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Commercial | Other commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	2,102	1,079
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Commercial | Lease financing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	444	2
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Commercial | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	0	164
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Noncommercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	13,114	13,731
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	598	669
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	7,039	7,536
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Revolving mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	2,698	3,704
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	2,779	1,822
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-PCI Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	37,904	39,349
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-PCI Loans | Commercial | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	286	463
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	10,329	14,495
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-PCI Loans | Commercial | Other commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	0	142
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,051	1,780
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-PCI Loans | Commercial | Lease financing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	863	164
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-PCI Loans | Commercial | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	198	134
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-PCI Loans | Noncommercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	25,177	22,171
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	557	1,638
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	15,280	13,280
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Revolving mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	7,414	5,631
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	$ 1,926	$ 1,622