Loans and Leases Loans and Leases (Credit Rating) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans and leases	$ 32,845,144	$ 28,881,496
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	7,336,119
2019	4,409,834
2018	2,996,446
2017	2,351,402
2016	1,805,161
Prior	2,643,319
Revolving loans	1,064,992
Revolving loans converted to term loans	6,659
Total loans and leases	22,613,932
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,934,598
2019	1,607,553
2018	1,063,837
2017	832,712
2016	614,953
Prior	1,089,254
Revolving loans	2,424,485
Revolving loans converted to term loans	167,942
Total loans and leases	9,735,334
Consumer And PCD Portfolio Segments
Financing Receivable, Credit Quality Indicator [Line Items]
2020	9,298,534
2019	6,045,888
2018	4,095,610
2017	3,220,557
2016	2,453,779
Prior	4,027,428
Revolving loans	3,504,200
Revolving loans converted to term loans	199,148
Total loans and leases	32,845,144
Construction and land development | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	247,655
2019	397,154
2018	210,500
2017	137,954
2016	35,788
Prior	13,226
Revolving loans	11,909
Revolving loans converted to term loans	0
Total loans and leases	1,054,186
Construction and land development | Commercial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	247,187
2019	396,322
2018	208,736
2017	132,518
2016	35,780
Prior	13,144
Revolving loans	11,909
Revolving loans converted to term loans	0
Total loans and leases	1,045,596
Construction and land development | Commercial | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	176
2019	0
2018	312
2017	5,436
2016	0
Prior	0
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	5,924
Construction and land development | Commercial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	292
2019	832
2018	1,452
2017	0
2016	8
Prior	82
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	2,666
Construction and land development | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	144,809
2019	140,820
2018	29,866
2017	13,145
2016	6,835
Prior	3,886
Revolving loans	8,489
Revolving loans converted to term loans	0
Total loans and leases	347,850
Owner occupied commercial mortgage | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	2,121,839
2019	2,256,713
2018	1,778,295
2017	1,460,654
2016	1,175,153
Prior	1,780,213
Revolving loans	110,748
Revolving loans converted to term loans	207
Total loans and leases	10,683,822
Owner occupied commercial mortgage | Commercial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	2,098,636
2019	2,218,063
2018	1,731,557
2017	1,423,847
2016	1,146,027
Prior	1,714,102
Revolving loans	101,547
Revolving loans converted to term loans	135
Total loans and leases	10,433,914
Owner occupied commercial mortgage | Commercial | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	5,578
2019	24,032
2018	37,273
2017	12,246
2016	17,433
Prior	27,905
Revolving loans	3,313
Revolving loans converted to term loans	0
Total loans and leases	127,780
Owner occupied commercial mortgage | Commercial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	17,625
2019	14,618
2018	9,465
2017	24,561
2016	11,693
Prior	38,206
Revolving loans	5,888
Revolving loans converted to term loans	72
Total loans and leases	122,128
Non-owner occupied commercial mortgage | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	662,830
2019	644,682
2018	431,809
2017	380,705
2016	320,155
Prior	487,642
Revolving loans	38,081
Revolving loans converted to term loans	0
Total loans and leases	2,965,904
Non-owner occupied commercial mortgage | Commercial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	660,088
2019	624,860
2018	407,230
2017	372,287
2016	304,782
Prior	469,429
Revolving loans	35,321
Revolving loans converted to term loans	0
Total loans and leases	2,873,997
Non-owner occupied commercial mortgage | Commercial | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	355
2019	701
2018	11,740
2017	1,500
2016	5,213
Prior	3,340
Revolving loans	777
Revolving loans converted to term loans	0
Total loans and leases	23,626
Non-owner occupied commercial mortgage | Commercial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	2,387
2019	19,121
2018	12,839
2017	6,918
2016	10,160
Prior	14,873
Revolving loans	1,983
Revolving loans converted to term loans	0
Total loans and leases	68,281
Commercial and industrial | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,191,119
2019	1,111,285
2018	575,842
2017	372,089
2016	274,065
Prior	362,238
Revolving loans	904,254
Revolving loans converted to term loans	6,452
Total loans and leases	4,797,344
Commercial and industrial | Commercial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,175,036
2019	1,090,278
2018	562,547
2017	361,442
2016	267,706
Prior	352,946
Revolving loans	809,256
Revolving loans converted to term loans	5,433
Total loans and leases	4,624,644
Commercial and industrial | Commercial | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,713
2019	17,409
2018	8,908
2017	5,631
2016	3,641
Prior	4,607
Revolving loans	13,673
Revolving loans converted to term loans	216
Total loans and leases	57,798
Commercial and industrial | Commercial | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
2020	12,370
2019	3,598
2018	4,387
2017	5,016
2016	2,707
Prior	4,685
Revolving loans	25,096
Revolving loans converted to term loans	803
Total loans and leases	58,662
Commercial and industrial | Commercial | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	11
Prior	0
Revolving loans	2
Revolving loans converted to term loans	0
Total loans and leases	13
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	56,227
Revolving loans converted to term loans	0
Total loans and leases	56,227
Residential mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,351,057
2019	1,050,243
2018	767,401
2017	688,115
2016	537,069
Prior	1,039,847
Revolving loans	29,914
Revolving loans converted to term loans	0
Total loans and leases	5,463,646
Revolving mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	1,977,564
Revolving loans converted to term loans	167,942
Total loans and leases	2,145,506
Consumer auto | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	398,867
2019	383,007
2018	251,917
2017	123,592
2016	61,719
Prior	15,094
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	1,234,196
Consumer other | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	39,865
2019	33,483
2018	14,653
2017	7,860
2016	9,330
Prior	30,427
Revolving loans	408,518
Revolving loans converted to term loans	0
Total loans and leases	544,136
SBA-PPP | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,112,676
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	3,112,676
SBA-PPP | Commercial | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,112,676
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	3,112,676
PCD Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	27,817
2019	28,501
2018	35,327
2017	36,443
2016	33,665
Prior	294,855
Revolving loans	14,723
Revolving loans converted to term loans	24,547
Total loans and leases	495,878	$ 558,716
Current | Construction and land development | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	144,559
2019	140,794
2018	29,400
2017	13,049
2016	6,818
Prior	3,721
Revolving loans	8,274
Revolving loans converted to term loans	0
Total loans and leases	346,615
Current | Residential mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,349,415
2019	1,044,542
2018	754,024
2017	677,727
2016	524,014
Prior	1,006,894
Revolving loans	26,857
Revolving loans converted to term loans	0
Total loans and leases	5,383,473
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	1,969,703
Revolving loans converted to term loans	158,236
Total loans and leases	2,127,939
Current | Consumer auto | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	398,216
2019	380,919
2018	250,602
2017	122,352
2016	61,076
Prior	14,817
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	1,227,982
Current | Consumer other | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	39,667
2019	33,269
2018	14,505
2017	7,832
2016	9,269
Prior	30,406
Revolving loans	401,907
Revolving loans converted to term loans	0
Total loans and leases	536,855
Current | PCD Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	24,169
2019	24,565
2018	29,739
2017	34,617
2016	32,149
Prior	262,095
Revolving loans	14,236
Revolving loans converted to term loans	22,371
Total loans and leases	443,941
30 to 59 Days past due | Construction and land development | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	250
2019	26
2018	466
2017	96
2016	17
Prior	68
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	923
30 to 59 Days past due | Residential mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,450
2019	3,274
2018	10,486
2017	6,124
2016	4,627
Prior	11,875
Revolving loans	85
Revolving loans converted to term loans	0
Total loans and leases	37,921
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	4,993
Revolving loans converted to term loans	3,484
Total loans and leases	8,477
30 to 59 Days past due | Consumer auto | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	492
2019	1,400
2018	823
2017	889
2016	425
Prior	216
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	4,245
30 to 59 Days past due | Consumer other | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	145
2019	92
2018	109
2017	12
2016	61
Prior	21
Revolving loans	4,050
Revolving loans converted to term loans	0
Total loans and leases	4,490
30 to 59 Days past due | PCD Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,531
2019	710
2018	940
2017	438
2016	691
Prior	9,575
Revolving loans	215
Revolving loans converted to term loans	198
Total loans and leases	16,298
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	0
2016	0
Prior	0
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	0
60 to 89 Days past due | Residential mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	19
2019	854
2018	187
2017	316
2016	2,241
Prior	2,194
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	5,811
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	419
Revolving loans converted to term loans	1,163
Total loans and leases	1,582
60 to 89 Days past due | Consumer auto | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	120
2019	382
2018	224
2017	160
2016	164
Prior	9
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	1,059
60 to 89 Days past due | Consumer other | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	46
2019	42
2018	31
2017	15
2016	0
Prior	0
Revolving loans	1,190
Revolving loans converted to term loans	0
Total loans and leases	1,324
60 to 89 Days past due | PCD Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	337
2018	54
2017	155
2016	52
Prior	2,054
Revolving loans	218
Revolving loans converted to term loans	331
Total loans and leases	3,201
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	97
Revolving loans	215
Revolving loans converted to term loans	0
Total loans and leases	312
90 Days or greater | Residential mortgage | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	173
2019	1,573
2018	2,704
2017	3,948
2016	6,187
Prior	18,884
Revolving loans	2,972
Revolving loans converted to term loans	0
Total loans and leases	36,441
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	2,449
Revolving loans converted to term loans	5,059
Total loans and leases	7,508
90 Days or greater | Consumer auto | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	39
2019	306
2018	268
2017	191
2016	54
Prior	52
Revolving loans	0
Revolving loans converted to term loans	0
Total loans and leases	910
90 Days or greater | Consumer other | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2020	7
2019	80
2018	8
2017	1
2016	0
Prior	0
Revolving loans	1,371
Revolving loans converted to term loans	0
Total loans and leases	1,467
90 Days or greater | PCD Loans
Financing Receivable, Credit Quality Indicator [Line Items]
2020	117
2019	2,889
2018	4,594
2017	1,233
2016	773
Prior	21,131
Revolving loans	54
Revolving loans converted to term loans	1,647
Total loans and leases	$ 32,438