Loans and Allowances for Credit Losses, By Aging Category (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Accruing	$ 76,114	$ 119,132
Current and Past Due Performing Loans	22,557,150	20,205,680
Current
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	22,355,864	19,980,847
30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	55,039	43,102
60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	51,614	27,870
90 Days or More [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	94,633	153,861
Commercial [Member]
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Accruing	0	199
Current and Past Due Performing Loans	14,198,187	12,506,465
Commercial [Member] | Current
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	14,156,787	12,472,930
Commercial [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	7,024	9,904
Commercial [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	28,959	9,333
Commercial [Member] | 90 Days or More [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	5,417	14,298
Commercial [Member] | Healthcare [Member]
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Accruing	0	0
Current and Past Due Performing Loans	3,845,017	3,414,940
Commercial [Member] | Healthcare [Member] | Current
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	3,812,164	3,412,072
Commercial [Member] | Healthcare [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	5,914	2,359
Commercial [Member] | Healthcare [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	26,480	0
Commercial [Member] | Healthcare [Member] | 90 Days or More [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	459	509
Commercial [Member] | Energy [Member]
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Accruing	0	0
Current and Past Due Performing Loans	3,424,790	3,006,884
Commercial [Member] | Energy [Member] | Current
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	3,424,766	3,002,623
Commercial [Member] | Energy [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	24	545
Commercial [Member] | Energy [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	0	3,716
Commercial [Member] | Energy [Member] | 90 Days or More [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	0	0
Commercial [Member] | Services [Member]
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Accruing	0	0
Current and Past Due Performing Loans	3,431,521	3,367,193
Commercial [Member] | Services [Member] | Current
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	3,423,042	3,352,639
Commercial [Member] | Services [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	1,060	920
Commercial [Member] | Services [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	2,461	4,620
Commercial [Member] | Services [Member] | 90 Days or More [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	4,958	9,014
Commercial [Member] | General business [Member]
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Accruing	0	199
Current and Past Due Performing Loans	3,496,859	2,717,448
Commercial [Member] | General business [Member] | Current
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	3,496,815	2,705,596
Commercial [Member] | General business [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	26	6,080
Commercial [Member] | General business [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	18	997
Commercial [Member] | General business [Member] | 90 Days or More [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	0	4,775
Commercial real estate [Member]
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Accruing	0	0
Current and Past Due Performing Loans	4,606,777	3,831,325
Commercial real estate [Member] | Current
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	4,606,029	3,827,962
Commercial real estate [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	531	0
Commercial real estate [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	0	206
Commercial real estate [Member] | 90 Days or More [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	217	3,157
Paycheck Protection Program
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Accruing	396	74
Current and Past Due Performing Loans	14,312	276,341
Paycheck Protection Program | Current
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	12,279	276,341
Paycheck Protection Program | 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	231	0
Paycheck Protection Program | 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	1,406	0
Paycheck Protection Program | 90 Days or More [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	396	0
Loans to individuals [Member]
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Accruing	75,718	118,859
Current and Past Due Performing Loans	3,737,874	3,591,549
Loans to individuals [Member] | Current
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	3,580,769	3,403,614
Loans to individuals [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	47,253	33,198
Loans to individuals [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	21,249	18,331
Loans to individuals [Member] | 90 Days or More [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	88,603	136,406
Loans to individuals [Member] | Residential mortgage [Member]
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Accruing	114	0
Current and Past Due Performing Loans	1,890,784	1,722,170
Loans to individuals [Member] | Residential mortgage [Member] | Current
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	1,872,155	1,707,654
Loans to individuals [Member] | Residential mortgage [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	10,632	6,263
Loans to individuals [Member] | Residential mortgage [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	1,828	1,556
Loans to individuals [Member] | Residential mortgage [Member] | 90 Days or More [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	6,169	6,697
Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Accruing	75,604	118,819
Current and Past Due Performing Loans	245,940	354,173
Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans | Current
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	108,019	181,022
Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans | 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	36,119	26,869
Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans | 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	19,400	16,751
Loans to individuals [Member] | Residential mortgage [Member] | US Government Agency Insured Loans | 90 Days or More [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	82,402	129,531
Loans to individuals [Member] | Personal [Member]
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Accruing	0	40
Current and Past Due Performing Loans	1,601,150	1,515,206
Loans to individuals [Member] | Personal [Member] | Current
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	1,600,595	1,514,938
Loans to individuals [Member] | Personal [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	502	66
Loans to individuals [Member] | Personal [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	21	24
Loans to individuals [Member] | Personal [Member] | 90 Days or More [Member]
Financing Receivable, Past Due [Line Items]
Current and Past Due Performing Loans	$ 32	$ 178