Loans and Leases (Aging Of The Outstanding Loans and Leases By Class) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Past due loans	$ 277,651	$ 206,535
Current loans	28,963,308	28,116,245
Total loans and leases	29,240,959	28,322,780
Commercial
Financing Receivable, Past Due [Line Items]
Total loans and leases	18,886,482
Commercial | Construction and land development
Financing Receivable, Past Due [Line Items]
Total loans and leases	1,014,017
Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total loans and leases	4,738,098
Consumer
Financing Receivable, Past Due [Line Items]
Total loans and leases	9,794,125
Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Total loans and leases	363,190
Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	5,299,412
Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	2,362,644
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	5,737	6,043
Current loans	1,008,280	1,007,411
Total loans and leases	1,014,017	1,013,454
Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	40,375	37,482
Current loans	10,035,757	12,245,153
Total loans and leases	10,076,132	12,282,635
Non-PCI Loans | Commercial | Other commercial real estate
Financing Receivable, Past Due [Line Items]
Past due loans	14,376	1,890
Current loans	3,043,859	540,138
Total loans and leases	3,058,235	542,028
Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Past due loans	29,250	28,143
Current loans	4,708,848	4,375,649
Total loans and leases	4,738,098	4,403,792
Non-PCI Loans | Commercial | Other
Financing Receivable, Past Due [Line Items]
Past due loans	89,738	588
Current loans	18,796,744	309,505
Total loans and leases	18,886,482	310,093
Non-PCI Loans | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	123,644	132,389
Current loans	9,670,481	9,638,389
Total loans and leases	9,794,125	9,770,778
Non-PCI Loans | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Past due loans	8,341	2,992
Current loans	1,192,811	354,393
Total loans and leases	1,201,152	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	78,072
Current loans	5,221,340
Total loans and leases	5,299,412
Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	21,588
Current loans	2,341,056
Total loans and leases	2,362,644
Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	7,645	23,062
Current loans	355,545	2,316,010
Total loans and leases	363,190	2,339,072
Non-PCI Loans | Consumer | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	7,998	17,798
Current loans	559,729	1,762,606
Total loans and leases	567,727	1,780,404
PCD Loans
Financing Receivable, Past Due [Line Items]
Past due loans	64,269
Current loans	496,083
Total loans and leases	560,352
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	146,672	109,742
30 to 59 Days past due | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Total loans and leases	6,089
30 to 59 Days past due | Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	40,149
30 to 59 Days past due | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	10,145
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	3,297	3,146
30 to 59 Days past due | Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	22,793	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	9,173	861
30 to 59 Days past due | Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Past due loans	18,076	18,269
30 to 59 Days past due | Non-PCI Loans | Commercial | Other
Financing Receivable, Past Due [Line Items]
Past due loans	53,339	51
30 to 59 Days past due | Non-PCI Loans | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	65,705	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	5,675	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	40,149
30 to 59 Days past due | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	10,145
30 to 59 Days past due | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	6,089	9,729
30 to 59 Days past due | Non-PCI Loans | Consumer | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	3,647	10,481
30 to 59 Days past due | PCD Loans
Financing Receivable, Past Due [Line Items]
Past due loans	27,628
Total loans and leases	27,628
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	34,001	40,274
60 to 89 Days past due | Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	8,015
60 to 89 Days past due | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	3,410
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	342	195
60 to 89 Days past due | Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	3,083	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	308	331
60 to 89 Days past due | Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Past due loans	6,924	4,842
60 to 89 Days past due | Non-PCI Loans | Commercial | Other
Financing Receivable, Past Due [Line Items]
Past due loans	10,657	411
60 to 89 Days past due | Non-PCI Loans | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	14,664	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	1,181	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	8,015
60 to 89 Days past due | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	3,410
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	2,058	3,746
60 to 89 Days past due | PCD Loans
Financing Receivable, Past Due [Line Items]
Past due loans	8,680
Total loans and leases	8,680
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	96,978	56,519
90 Days or greater | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Total loans and leases	1,556
90 Days or greater | Consumer | Residential mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	29,908
90 Days or greater | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Total loans and leases	8,033
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	2,098	2,702
90 Days or greater | Non-PCI Loans | Commercial | Mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	14,499	8,319
90 Days or greater | Non-PCI Loans | Commercial | Other commercial real estate
Financing Receivable, Past Due [Line Items]
Past due loans	4,895	698
90 Days or greater | Non-PCI Loans | Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Past due loans	4,250	5,032
90 Days or greater | Non-PCI Loans | Commercial | Other
Financing Receivable, Past Due [Line Items]
Past due loans	25,742	126
90 Days or greater | Non-PCI Loans | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	43,275	39,642
90 Days or greater | Non-PCI Loans | Consumer | Construction and land development
Financing Receivable, Past Due [Line Items]
Past due loans	1,485	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	29,908
90 Days or greater | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	8,033
90 Days or greater | Non-PCI Loans | Consumer | Revolving mortgage
Financing Receivable, Past Due [Line Items]
Past due loans	1,556	9,865
90 Days or greater | Non-PCI Loans | Consumer | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans	2,293	3,571
90 Days or greater | PCD Loans
Financing Receivable, Past Due [Line Items]
Past due loans	27,961
Total loans and leases	$ 27,961
90 Days or greater | PCD Loans | Consumer
Financing Receivable, Past Due [Line Items]
Past due loans		$ 14,020