Loans and Leases (Aging Of The Outstanding Loans and Leases By Class) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Past due loans	$ 228,304	$ 272,770
Current loans	32,190,121	28,608,726
Total loans and leases	32,418,425	28,881,496
Commercial
Financing Receivable, Past Due [Line Items]
Total loans and leases	22,156,874
Commercial | Construction and land development
Financing Receivable, Past Due [Line Items]
Total loans and leases	1,012,365
Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total loans and leases	4,650,839
Commercial | SBA-PPP
Financing Receivable, Past Due [Line Items]
Total loans and leases	3,084,549
Consumer
Financing Receivable, Past Due [Line Items]
Total loans and leases	9,730,900
Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Total loans and leases	353,382
Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	5,404,682
Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	2,233,977
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	3,353	6,043
Current loans	1,009,012	1,007,411
Total loans and leases	1,012,365	1,013,454
Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	29,698	37,482
Current loans	10,323,095	12,245,153
Total loans and leases	10,352,793	12,282,635
Non-PCI Loans | Commercial | Other commercial real estate
Financing Receivable, Past Due [Line Items]
Past due loans	17,416	1,890
Current loans	3,038,912	540,138
Total loans and leases	3,056,328	542,028
Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Past due loans	17,875	28,143
Current loans	4,632,964	4,375,649
Total loans and leases	4,650,839	4,403,792
Non-PCI Loans | Commercial | Other
Financing Receivable, Past Due [Line Items]
Past due loans	68,342	588
Current loans	22,088,532	309,505
Total loans and leases	22,156,874	310,093
Non-PCI Loans | Commercial | SBA-PPP
Financing Receivable, Past Due [Line Items]
Past due loans	0
Current loans	3,084,549
Total loans and leases	3,084,549
Non-PCI Loans | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	102,935	132,389
Current loans	9,627,965	9,638,389
Total loans and leases	9,730,900	9,770,778
Non-PCI Loans | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Past due loans	5,193	2,992
Current loans	1,190,578	354,393
Total loans and leases	1,195,771	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	67,369
Current loans	5,337,313
Total loans and leases	5,404,682
Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	22,495
Current loans	2,211,482
Total loans and leases	2,233,977
Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	1,919	23,062
Current loans	351,463	2,316,010
Total loans and leases	353,382	2,339,072
Non-PCI Loans | Consumer | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	5,959	17,798
Current loans	537,129	1,762,606
Total loans and leases	543,088	1,780,404
PCD Loans
Financing Receivable, Past Due [Line Items]
Past due loans	57,027	66,235
Current loans	473,624	492,481
Total loans and leases	530,651	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	94,584	136,220
30 to 59 Days past due | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Total loans and leases	1,735
30 to 59 Days past due | Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	25,243
30 to 59 Days past due | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	8,874
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	1,618	3,146
30 to 59 Days past due | Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	14,360	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	7,914	861
30 to 59 Days past due | Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Past due loans	10,464	18,269
30 to 59 Days past due | Non-PCI Loans | Commercial | Other
Financing Receivable, Past Due [Line Items]
Past due loans	34,356	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	41,378	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	3,093	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	25,243
30 to 59 Days past due | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	8,874
30 to 59 Days past due | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	1,735	9,729
30 to 59 Days past due | Non-PCI Loans | Consumer | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	2,433	10,481
30 to 59 Days past due | PCD Loans
Financing Receivable, Past Due [Line Items]
Past due loans	18,850	26,478
Total loans and leases	18,850
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	26,043	51,058
60 to 89 Days past due | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Total loans and leases	127
60 to 89 Days past due | Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	7,082
60 to 89 Days past due | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	4,615
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	14	195
60 to 89 Days past due | Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	2,518	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	982	331
60 to 89 Days past due | Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Past due loans	3,196	4,842
60 to 89 Days past due | Non-PCI Loans | Commercial | Other
Financing Receivable, Past Due [Line Items]
Past due loans	6,710	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	14,639	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	1,124	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	7,082
60 to 89 Days past due | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	4,615
60 to 89 Days past due | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	127	3,468
60 to 89 Days past due | Non-PCI Loans | Consumer | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	1,691	3,746
60 to 89 Days past due | PCD Loans
Financing Receivable, Past Due [Line Items]
Past due loans	4,694	10,784
Total loans and leases	4,694
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	107,677	85,492
90 Days or greater | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Total loans and leases	57
90 Days or greater | Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	35,044
90 Days or greater | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	9,006
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	1,721	2,702
90 Days or greater | Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	12,820	8,319
90 Days or greater | Non-PCI Loans | Commercial | Other commercial real estate
Financing Receivable, Past Due [Line Items]
Past due loans	8,520	698
90 Days or greater | Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Past due loans	4,215	5,032
90 Days or greater | Non-PCI Loans | Commercial | Other
Financing Receivable, Past Due [Line Items]
Past due loans	27,276	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	46,918	39,642
90 Days or greater | Non-PCI Loans | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Past due loans	976	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	35,044
90 Days or greater | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	9,006
90 Days or greater | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	57	9,865
90 Days or greater | Non-PCI Loans | Consumer | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	1,835	3,571
90 Days or greater | PCD Loans
Financing Receivable, Past Due [Line Items]
Past due loans	33,483	28,973
Total loans and leases	$ 33,483
90 Days or greater | PCD Loans | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans		$ 14,020