Loans and Leases (Aging Of The Outstanding Loans and Leases By Class Excluding Loans Impaired At Acquisition Date) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	$ 19,289,474	$ 17,582,967
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	12,630,489	11,205,639
Commercial | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	620,352	493,133
Commercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	8,274,548	7,552,948
Commercial | Other commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	321,021	244,875
Commercial | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	2,368,958	1,988,934
Commercial | Lease financing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	730,778	571,916
Commercial | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	314,832	353,833
Noncommercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	6,658,985	6,377,328
Noncommercial | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	220,073	205,016
Noncommercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	2,695,985	2,493,058
Noncommercial | Revolving mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	2,523,106	2,561,800
Noncommercial | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-PCI Loans	1,219,821	1,117,454
Non-PCI Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	121,576	101,467
Current	19,167,898	17,481,500
Non-PCI Loans	19,289,474	17,582,967
Non-PCI Loans | Commercial | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,733	1,133
Current	618,619	492,000
Non-PCI Loans	620,352	493,133
Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	30,964	24,210
Current	8,243,584	7,528,738
Non-PCI Loans	8,274,548	7,552,948
Non-PCI Loans | Commercial | Other commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,026	378
Current	319,995	244,497
Non-PCI Loans	321,021	244,875
Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	4,992	4,766
Current	2,363,966	1,984,168
Non-PCI Loans	2,368,958	1,988,934
Non-PCI Loans | Commercial | Lease financing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	2,236	1,641
Current	728,542	570,275
Non-PCI Loans	730,778	571,916
Non-PCI Loans | Commercial | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	301	2,112
Current	314,531	351,721
Non-PCI Loans	314,832	353,833
Non-PCI Loans | Noncommercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	6,578,661	6,310,101
Non-PCI Loans	6,658,985	6,377,328
Non-PCI Loans | Noncommercial | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	5,518	2,672
Current	214,555	202,344
Non-PCI Loans	220,073	205,016
Non-PCI Loans | Noncommercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	44,776	38,261
Current	2,651,209	2,454,797
Non-PCI Loans	2,695,985	2,493,058
Non-PCI Loans | Noncommercial | Revolving mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	21,041	18,993
Current	2,502,065	2,542,807
Non-PCI Loans	2,523,106	2,561,800
Non-PCI Loans | Noncommercial | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	8,989	7,301
Current	1,210,832	1,110,153
Non-PCI Loans	1,219,821	1,117,454
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	63,522	57,321
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	987	520
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	13,023	11,367
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	884	206
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	2,133	2,843
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Commercial | Lease financing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	2,070	1,631
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Commercial | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	3	146
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Noncommercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	44,422	40,608
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	3,211	1,646
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	23,960	23,288
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Revolving mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	11,706	11,097
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	5,545	4,577
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	18,705	19,548
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	283	283
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	3,446	4,782
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	70
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	1,079	1,545
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Commercial | Lease financing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	2	8
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Commercial | Other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	164	1,966
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Noncommercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	13,731	10,894
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	669	824
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	7,536	6,018
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Revolving mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	3,704	2,433
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-PCI Loans | Noncommercial | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,822	1,619
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-PCI Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	39,349	24,598
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	463	330
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	14,495	8,061
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	142	102
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	1,780	378
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	164	2
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	134	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Non-PCI Loans | Noncommercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	22,171	15,725
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	1,638	202
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	13,280	8,955
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	5,631	5,463
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	$ 1,622	$ 1,105