Loans and Leases (Aging Of The Outstanding Loans and Leases By Class) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Past due loans	$ 249,119	$ 272,770
Current loans	32,596,025	28,608,726
Total loans and leases	32,845,144	28,881,496
Commercial
Financing Receivable, Past Due [Line Items]
Total loans and leases	22,613,932
Commercial | Construction and land development
Financing Receivable, Past Due [Line Items]
Total loans and leases	1,054,186
Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total loans and leases	4,797,344
Commercial | SBA-PPP
Financing Receivable, Past Due [Line Items]
Total loans and leases	3,112,676
Consumer
Financing Receivable, Past Due [Line Items]
Total loans and leases	9,735,334
Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Total loans and leases	347,850
Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	5,463,646
Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	2,145,506
Non-PCI Loans | Commercial
Financing Receivable, Past Due [Line Items]
Past due loans		74,146
Current loans		18,477,856
Total loans and leases		18,552,002
Non-PCI Loans | Commercial | Construction and land development
Financing Receivable, Past Due [Line Items]
Past due loans	9,362	6,043
Current loans	1,044,824	1,007,411
Total loans and leases	1,054,186	1,013,454
Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	35,261	37,482
Current loans	10,648,561	12,245,153
Total loans and leases	10,683,822	12,282,635
Non-PCI Loans | Commercial | Other commercial real estate
Financing Receivable, Past Due [Line Items]
Past due loans	23,906	1,890
Current loans	2,941,998	540,138
Total loans and leases	2,965,904	542,028
Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Past due loans	16,183	28,143
Current loans	4,781,161	4,375,649
Total loans and leases	4,797,344	4,403,792
Non-PCI Loans | Commercial | Other
Financing Receivable, Past Due [Line Items]
Past due loans	84,712	588
Current loans	22,529,220	309,505
Total loans and leases	22,613,932	310,093
Non-PCI Loans | Commercial | SBA-PPP
Financing Receivable, Past Due [Line Items]
Past due loans	0
Current loans	3,112,676
Total loans and leases	3,112,676
Non-PCI Loans | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	112,470	132,389
Current loans	9,622,864	9,638,389
Total loans and leases	9,735,334	9,770,778
Non-PCI Loans | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Past due loans	6,214	2,992
Current loans	1,227,982	354,393
Total loans and leases	1,234,196	357,385
Non-PCI Loans | Consumer | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans		88,537
Current loans		5,205,380
Total loans and leases		5,293,917
Non-PCI Loans | Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	80,173
Current loans	5,383,473
Total loans and leases	5,463,646
Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	17,567
Current loans	2,127,939
Total loans and leases	2,145,506
Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	1,235	23,062
Current loans	346,615	2,316,010
Total loans and leases	347,850	2,339,072
Non-PCI Loans | Consumer | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	7,281	17,798
Current loans	536,855	1,762,606
Total loans and leases	544,136	1,780,404
PCD Loans
Financing Receivable, Past Due [Line Items]
Past due loans	51,937	66,235
Current loans	443,941	492,481
Total loans and leases	495,878	558,716
PCD Loans | Consumer
Financing Receivable, Past Due [Line Items]
Current loans		240,995
30 to 59 Days past due
Financing Receivable, Past Due [Line Items]
Past due loans	121,823	136,220
30 to 59 Days past due | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Total loans and leases	923
30 to 59 Days past due | Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	37,921
30 to 59 Days past due | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	8,477
30 to 59 Days past due | Non-PCI Loans | Commercial
Financing Receivable, Past Due [Line Items]
Past due loans		42,716
30 to 59 Days past due | Non-PCI Loans | Commercial | Construction and land development
Financing Receivable, Past Due [Line Items]
Past due loans	7,860	3,146
30 to 59 Days past due | Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	23,354	20,389
30 to 59 Days past due | Non-PCI Loans | Commercial | Other commercial real estate
Financing Receivable, Past Due [Line Items]
Past due loans	9,854	861
30 to 59 Days past due | Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Past due loans	8,401	18,269
30 to 59 Days past due | Non-PCI Loans | Commercial | Other
Financing Receivable, Past Due [Line Items]
Past due loans	49,469	51
30 to 59 Days past due | Non-PCI Loans | Commercial | SBA-PPP
Financing Receivable, Past Due [Line Items]
Past due loans	0
30 to 59 Days past due | Non-PCI Loans | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	56,056	67,026
30 to 59 Days past due | Non-PCI Loans | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Past due loans	4,245	977
30 to 59 Days past due | Non-PCI Loans | Consumer | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans		45,839
30 to 59 Days past due | Non-PCI Loans | Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	37,921
30 to 59 Days past due | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	8,477
30 to 59 Days past due | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	923	9,729
30 to 59 Days past due | Non-PCI Loans | Consumer | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	4,490	10,481
30 to 59 Days past due | PCD Loans
Financing Receivable, Past Due [Line Items]
Past due loans	16,298	26,478
Total loans and leases	16,298
30 to 59 Days past due | PCD Loans | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans		13,764
60 to 89 Days past due
Financing Receivable, Past Due [Line Items]
Past due loans	29,490	51,058
60 to 89 Days past due | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Total loans and leases	0
60 to 89 Days past due | Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	5,811
60 to 89 Days past due | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	1,582
60 to 89 Days past due | Non-PCI Loans | Commercial
Financing Receivable, Past Due [Line Items]
Past due loans		14,553
60 to 89 Days past due | Non-PCI Loans | Commercial | Construction and land development
Financing Receivable, Past Due [Line Items]
Past due loans	0	195
60 to 89 Days past due | Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	5,212	8,774
60 to 89 Days past due | Non-PCI Loans | Commercial | Other commercial real estate
Financing Receivable, Past Due [Line Items]
Past due loans	7,381	331
60 to 89 Days past due | Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Past due loans	3,920	4,842
60 to 89 Days past due | Non-PCI Loans | Commercial | Other
Financing Receivable, Past Due [Line Items]
Past due loans	16,513	411
60 to 89 Days past due | Non-PCI Loans | Commercial | SBA-PPP
Financing Receivable, Past Due [Line Items]
Past due loans	0
60 to 89 Days past due | Non-PCI Loans | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	9,776	25,721
60 to 89 Days past due | Non-PCI Loans | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Past due loans	1,059	218
60 to 89 Days past due | Non-PCI Loans | Consumer | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans		18,289
60 to 89 Days past due | Non-PCI Loans | Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	5,811
60 to 89 Days past due | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	1,582
60 to 89 Days past due | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	0	3,468
60 to 89 Days past due | Non-PCI Loans | Consumer | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	1,324	3,746
60 to 89 Days past due | PCD Loans
Financing Receivable, Past Due [Line Items]
Past due loans	3,201	10,784
Total loans and leases	3,201
60 to 89 Days past due | PCD Loans | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans		5,608
90 Days or greater
Financing Receivable, Past Due [Line Items]
Past due loans	97,806	85,492
90 Days or greater | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Total loans and leases	312
90 Days or greater | Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	36,441
90 Days or greater | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	7,508
90 Days or greater | Non-PCI Loans | Commercial
Financing Receivable, Past Due [Line Items]
Past due loans		16,877
90 Days or greater | Non-PCI Loans | Commercial | Construction and land development
Financing Receivable, Past Due [Line Items]
Past due loans	1,502	2,702
90 Days or greater | Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	6,695	8,319
90 Days or greater | Non-PCI Loans | Commercial | Other commercial real estate
Financing Receivable, Past Due [Line Items]
Past due loans	6,671	698
90 Days or greater | Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Past due loans	3,862	5,032
90 Days or greater | Non-PCI Loans | Commercial | Other
Financing Receivable, Past Due [Line Items]
Past due loans	18,730	126
90 Days or greater | Non-PCI Loans | Commercial | SBA-PPP
Financing Receivable, Past Due [Line Items]
Past due loans	0
90 Days or greater | Non-PCI Loans | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	46,638	39,642
90 Days or greater | Non-PCI Loans | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Past due loans	910	1,797
90 Days or greater | Non-PCI Loans | Consumer | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans		24,409
90 Days or greater | Non-PCI Loans | Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	36,441
90 Days or greater | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	7,508
90 Days or greater | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	312	9,865
90 Days or greater | Non-PCI Loans | Consumer | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	1,467	3,571
90 Days or greater | PCD Loans
Financing Receivable, Past Due [Line Items]
Past due loans	32,438	28,973
Total loans and leases	$ 32,438
90 Days or greater | PCD Loans | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans		$ 14,020