Loans and Leases Loans and Leases (Credit Rating) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans and leases	$ 32,418,425	$ 28,881,496
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	5,763,712
2019	4,551,255
2018	3,272,285
2017	2,495,157
2016	1,946,996
Prior	3,043,040
Revolving loans	1,077,716
Revolving loans converted to term loans	6,713
Total loans and leases	22,156,874
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,253,939
2019	1,748,923
2018	1,202,020
2017	936,567
2016	696,022
Prior	1,223,287
Revolving loans	2,499,253
Revolving loans converted to term loans	170,889
Total loans and leases	9,730,900
Consumer And PCD Portfolio Segments
Financing Receivable, Credit Quality Indicator [Line Items]
2020	7,040,689
2019	6,332,840
2018	4,515,556
2017	3,473,332
2016	2,678,221
Prior	4,580,988
Revolving loans	3,592,738
Revolving loans converted to term loans	204,061
Total loans and leases	32,418,425
Construction and land development | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	176,795
2019	406,119
2018	219,702
2017	138,289
2016	31,607
Prior	14,712
Revolving loans	25,141
Revolving loans converted to term loans	0
Total loans and leases	1,012,365
Construction and land development | Commercial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	175,302
2019	404,898
2018	217,555
2017	132,753
2016	31,599
Prior	14,453
Revolving loans	25,141
Revolving loans converted to term loans	0
Total loans and leases	1,001,701
Construction and land development | Commercial | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	88
2019	0
2018	334
2017	5,507
2016	0
Prior	93
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	6,022
Construction and land development | Commercial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,405
2019	1,221
2018	1,813
2017	29
2016	8
Prior	166
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	4,642
Construction and land development | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	88,308
2019	175,638
2018	52,361
2017	16,920
2016	8,123
Prior	8,141
Revolving loans	3,891
Revolving loans converted to term loans	0
Total loans and leases	353,382
Owner occupied commercial mortgage | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,356,778
2019	2,242,068
2018	1,896,955
2017	1,489,425
2016	1,235,385
Prior	2,013,703
Revolving loans	118,270
Revolving loans converted to term loans	209
Total loans and leases	10,352,793
Owner occupied commercial mortgage | Commercial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,345,296
2019	2,218,595
2018	1,850,128
2017	1,452,273
2016	1,203,335
Prior	1,943,057
Revolving loans	106,274
Revolving loans converted to term loans	137
Total loans and leases	10,119,095
Owner occupied commercial mortgage | Commercial | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	2,296
2019	11,164
2018	29,941
2017	13,089
2016	17,795
Prior	30,315
Revolving loans	2,742
Revolving loans converted to term loans	0
Total loans and leases	107,342
Owner occupied commercial mortgage | Commercial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	9,186
2019	12,309
2018	16,886
2017	24,063
2016	14,255
Prior	40,331
Revolving loans	9,254
Revolving loans converted to term loans	72
Total loans and leases	126,356
Non-owner occupied commercial mortgage | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	381,506
2019	688,209
2018	514,582
2017	454,666
2016	372,494
Prior	605,882
Revolving loans	38,989
Revolving loans converted to term loans	0
Total loans and leases	3,056,328
Non-owner occupied commercial mortgage | Commercial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	380,269
2019	685,067
2018	490,693
2017	452,152
2016	360,096
Prior	595,139
Revolving loans	36,723
Revolving loans converted to term loans	0
Total loans and leases	3,000,139
Non-owner occupied commercial mortgage | Commercial | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	2,048
2018	20,236
2017	872
2016	5,885
Prior	7,658
Revolving loans	787
Revolving loans converted to term loans	0
Total loans and leases	37,486
Non-owner occupied commercial mortgage | Commercial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,237
2019	1,094
2018	3,653
2017	1,642
2016	6,513
Prior	3,085
Revolving loans	1,479
Revolving loans converted to term loans	0
Total loans and leases	18,703
Commercial and industrial | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	764,084
2019	1,214,859
2018	641,046
2017	412,777
2016	307,510
Prior	408,743
Revolving loans	895,316
Revolving loans converted to term loans	6,504
Total loans and leases	4,650,839
Commercial and industrial | Commercial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	750,806
2019	1,207,639
2018	630,297
2017	401,635
2016	301,561
Prior	401,284
Revolving loans	805,691
Revolving loans converted to term loans	5,565
Total loans and leases	4,504,478
Commercial and industrial | Commercial | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,431
2019	3,426
2018	6,387
2017	5,534
2016	3,159
Prior	2,518
Revolving loans	13,928
Revolving loans converted to term loans	243
Total loans and leases	36,626
Commercial and industrial | Commercial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	11,847
2019	3,794
2018	4,323
2017	5,608
2016	2,790
Prior	4,941
Revolving loans	22,084
Revolving loans converted to term loans	696
Total loans and leases	56,083
Commercial and industrial | Commercial | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	39
2017	0
2016	0
Prior	0
Revolving loans	2
Revolving loans converted to term loans	0
Total loans and leases	41
Commercial and industrial | Commercial | Ungraded
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	53,611
Revolving loans converted to term loans	0
Total loans and leases	53,611
Residential mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	892,333
2019	1,109,142
2018	846,656
2017	766,388
2016	601,903
Prior	1,161,496
Revolving loans	26,764
Revolving loans converted to term loans	0
Total loans and leases	5,404,682
Revolving mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	2,063,088
Revolving loans converted to term loans	170,889
Total loans and leases	2,233,977
Consumer auto | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	245,533
2019	423,177
2018	285,756
2017	143,643
2016	75,309
Prior	22,353
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	1,195,771
Consumer other | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	27,765
2019	40,966
2018	17,247
2017	9,616
2016	10,687
Prior	31,297
Revolving loans	405,510
Revolving loans converted to term loans	0
Total loans and leases	543,088
SBA-PPP | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,084,549
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	3,084,549
SBA-PPP | Commercial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,084,549
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	3,084,549
PCD Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	23,038
2019	32,662
2018	41,251
2017	41,608
2016	35,203
Prior	314,661
Revolving loans	15,769
Revolving loans converted to term loans	26,459
Total loans and leases	530,651	$ 558,716
Current | Construction and land development | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	88,063
2019	174,326
2018	52,270
2017	16,909
2016	8,123
Prior	7,881
Revolving loans	3,891
Revolving loans converted to term loans	0
Total loans and leases	351,463
Current | Residential mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	891,796
2019	1,105,486
2018	837,530
2017	755,457
2016	591,255
Prior	1,132,116
Revolving loans	23,673
Revolving loans converted to term loans	0
Total loans and leases	5,337,313
Current | Revolving mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	2,054,864
Revolving loans converted to term loans	156,618
Total loans and leases	2,211,482
Current | Consumer auto | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	245,264
2019	421,363
2018	284,557
2017	142,512
2016	74,782
Prior	22,100
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	1,190,578
Current | Consumer other | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	27,655
2019	40,769
2018	17,093
2017	9,585
2016	10,595
Prior	31,275
Revolving loans	400,157
Revolving loans converted to term loans	0
Total loans and leases	537,129
Current | PCD Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	21,462
2019	28,900
2018	32,863
2017	39,973
2016	33,294
Prior	278,266
Revolving loans	14,999
Revolving loans converted to term loans	23,867
Total loans and leases	473,624
30 to 59 Days past due | Construction and land development | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	245
2019	1,312
2018	91
2017	0
2016	0
Prior	87
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	1,735
30 to 59 Days past due | Residential mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	488
2019	2,760
2018	2,985
2017	4,612
2016	2,594
Prior	11,685
Revolving loans	119
Revolving loans converted to term loans	0
Total loans and leases	25,243
30 to 59 Days past due | Revolving mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	4,622
Revolving loans converted to term loans	4,252
Total loans and leases	8,874
30 to 59 Days past due | Consumer auto | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	172
2019	1,070
2018	654
2017	710
2016	319
Prior	168
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	3,093
30 to 59 Days past due | Consumer other | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	78
2019	33
2018	79
2017	31
2016	13
Prior	22
Revolving loans	2,177
Revolving loans converted to term loans	0
Total loans and leases	2,433
30 to 59 Days past due | PCD Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,005
2019	546
2018	199
2017	132
2016	808
Prior	15,591
Revolving loans	182
Revolving loans converted to term loans	387
Total loans and leases	18,850
60 to 89 Days past due | Construction and land development | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	11
2016	0
Prior	116
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	127
60 to 89 Days past due | Residential mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	26
2019	158
2018	326
2017	265
2016	1,851
Prior	4,456
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	7,082
60 to 89 Days past due | Revolving mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	452
Revolving loans converted to term loans	4,163
Total loans and leases	4,615
60 to 89 Days past due | Consumer auto | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	75
2019	432
2018	239
2017	215
2016	132
Prior	31
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	1,124
60 to 89 Days past due | Consumer other | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	31
2019	67
2018	70
2017	0
2016	5
Prior	0
Revolving loans	1,518
Revolving loans converted to term loans	0
Total loans and leases	1,691
60 to 89 Days past due | PCD Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	117
2019	141
2018	37
2017	34
2016	0
Prior	3,669
Revolving loans	72
Revolving loans converted to term loans	624
Total loans and leases	4,694
90 Days or greater | Construction and land development | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	57
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	57
90 Days or greater | Residential mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	23
2019	738
2018	5,815
2017	6,054
2016	6,203
Prior	13,239
Revolving loans	2,972
Revolving loans converted to term loans	0
Total loans and leases	35,044
90 Days or greater | Revolving mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	3,150
Revolving loans converted to term loans	5,856
Total loans and leases	9,006
90 Days or greater | Consumer auto | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	22
2019	312
2018	306
2017	206
2016	76
Prior	54
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	976
90 Days or greater | Consumer other | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1
2019	97
2018	5
2017	0
2016	74
Prior	0
Revolving loans	1,658
Revolving loans converted to term loans	0
Total loans and leases	1,835
90 Days or greater | PCD Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	454
2019	3,075
2018	8,152
2017	1,469
2016	1,101
Prior	17,135
Revolving loans	516
Revolving loans converted to term loans	1,581
Total loans and leases	$ 33,483