Loans and Allowance for Credit Losses (Disaggregation of Credit Quality Disclosures) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2022	$ 1,384,048	$ 5,076,311
Term Loans, Amortized Cost Basis by Origination Year, 2021	4,644,730	3,073,804
Term Loans, Amortized Cost Basis by Origination Year, 2020	2,817,198	2,114,506
Term Loans, Amortized Cost Basis by Origination Year, 2019	1,890,230	1,285,226
Term Loans, Amortized Cost Basis by Origination Year, 2018	1,139,932	1,003,833
Term Loans, Amortized Cost Basis by Origination Year, Prior	2,170,973	1,385,473
Revolving Loans	3,174,966	3,084,875
Revolving Loans Converted to Term Loans	80,590	102,974
Notes Receivable Gross	17,302,667	17,127,002
Total Commercial [Member] | Pass [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2022	1,326,731	4,946,459
Term Loans, Amortized Cost Basis by Origination Year, 2021	4,549,370	3,008,160
Term Loans, Amortized Cost Basis by Origination Year, 2020	2,750,447	2,035,849
Term Loans, Amortized Cost Basis by Origination Year, 2019	1,801,058	1,212,306
Term Loans, Amortized Cost Basis by Origination Year, 2018	1,068,711	937,639
Term Loans, Amortized Cost Basis by Origination Year, Prior	2,043,133	1,296,382
Revolving Loans	3,072,931	3,002,064
Revolving Loans Converted to Term Loans	74,369	80,535
Notes Receivable Gross	16,686,749	16,519,394
Total Commercial [Member] | Pass-Watch [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2022	21,757	68,421
Term Loans, Amortized Cost Basis by Origination Year, 2021	57,011	19,467
Term Loans, Amortized Cost Basis by Origination Year, 2020	24,746	31,598
Term Loans, Amortized Cost Basis by Origination Year, 2019	42,969	45,846
Term Loans, Amortized Cost Basis by Origination Year, 2018	43,367	27,188
Term Loans, Amortized Cost Basis by Origination Year, Prior	79,352	69,310
Revolving Loans	59,453	52,850
Revolving Loans Converted to Term Loans	4,792	5,714
Notes Receivable Gross	333,448	320,394
Total Commercial [Member] | Special Mention [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2022	4,110	17,536
Term Loans, Amortized Cost Basis by Origination Year, 2021	13,566	2,683
Term Loans, Amortized Cost Basis by Origination Year, 2020	5,128	10,296
Term Loans, Amortized Cost Basis by Origination Year, 2019	8,612	12,410
Term Loans, Amortized Cost Basis by Origination Year, 2018	12,472	10,669
Term Loans, Amortized Cost Basis by Origination Year, Prior	12,378	3,656
Revolving Loans	19,536	9,603
Revolving Loans Converted to Term Loans	456	6,243
Notes Receivable Gross	76,258	73,096
Total Commercial [Member] | Substandard [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2022	31,450	43,895
Term Loans, Amortized Cost Basis by Origination Year, 2021	24,783	43,494
Term Loans, Amortized Cost Basis by Origination Year, 2020	36,877	36,763
Term Loans, Amortized Cost Basis by Origination Year, 2019	37,591	14,664
Term Loans, Amortized Cost Basis by Origination Year, 2018	15,382	28,337
Term Loans, Amortized Cost Basis by Origination Year, Prior	36,110	16,125
Revolving Loans	23,046	20,358
Revolving Loans Converted to Term Loans	973	10,482
Notes Receivable Gross	206,212	214,118
Residential Mortgage and Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2022	170,573	581,378
Term Loans, Amortized Cost Basis by Origination Year, 2021	558,585	468,448
Term Loans, Amortized Cost Basis by Origination Year, 2020	488,024	357,851
Term Loans, Amortized Cost Basis by Origination Year, 2019	316,620	227,959
Term Loans, Amortized Cost Basis by Origination Year, 2018	200,774	325,063
Term Loans, Amortized Cost Basis by Origination Year, Prior	1,157,086	916,726
Revolving Loans	1,124,197	1,121,893
Revolving Loans Converted to Term Loans	4,815	7,962
Notes Receivable Gross	4,020,674	4,007,280
Residential Mortgage and Consumer [Member] | Performing [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2022	170,543	580,813
Term Loans, Amortized Cost Basis by Origination Year, 2021	557,335	467,497
Term Loans, Amortized Cost Basis by Origination Year, 2020	486,997	355,833
Term Loans, Amortized Cost Basis by Origination Year, 2019	314,321	223,494
Term Loans, Amortized Cost Basis by Origination Year, 2018	197,414	320,344
Term Loans, Amortized Cost Basis by Origination Year, Prior	1,131,990	892,361
Revolving Loans	1,123,451	1,120,461
Revolving Loans Converted to Term Loans	4,492	5,995
Notes Receivable Gross	3,986,543	3,966,798
Residential Mortgage and Consumer [Member] | Nonperforming [Member]
Accounts Notes And Loans Receivable [Line Items]
Term Loans, Amortized Cost Basis by Origination Year, 2022	30	565
Term Loans, Amortized Cost Basis by Origination Year, 2021	1,250	951
Term Loans, Amortized Cost Basis by Origination Year, 2020	1,027	2,018
Term Loans, Amortized Cost Basis by Origination Year, 2019	2,299	4,465
Term Loans, Amortized Cost Basis by Origination Year, 2018	3,360	4,719
Term Loans, Amortized Cost Basis by Origination Year, Prior	25,096	24,365
Revolving Loans	746	1,432
Revolving Loans Converted to Term Loans	323	1,967
Notes Receivable Gross	$ 34,131	$ 40,482