v3.26.1
Reportable Segments (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Segment Reporting Information [Line Items]    
Net interest income from external sources $ 342,554 $ 316,251
Net interest income (expense) from internal sources 0 0
Net interest and dividend income 342,554 316,251
Provision for credit losses 0 0
Net interest income after provision for credit losses 342,554 316,251
Noninterest Income 211,268 186,041
Personnel 211,174 214,185
Other Cost and Expense, Operating 142,992 133,344
Noninterest Expense 354,166 347,529
Corporate Expense Allocations 0 0
Net income before taxes 199,656 154,763
Assets, Average Outstanding 53,123,009 50,986,903
Operating Segments [Member]    
Segment Reporting Information [Line Items]    
Net interest income from external sources 278,972 254,105
Net interest income (expense) from internal sources (6,536) 25,907
Net interest and dividend income 272,436 280,012
Provision for credit losses 2,404 1,657
Net interest income after provision for credit losses 270,032 278,355
Noninterest Income 213,321 190,915
Personnel 146,146 142,656
Other Cost and Expense, Operating 97,824 87,326
Noninterest Expense 243,970 229,982
Corporate Expense Allocations 47,887 46,344
Net income before taxes 191,496 192,944
Assets, Average Outstanding 42,502,541 40,970,001
Operating Segments [Member] | Commercial Banking [Member]    
Segment Reporting Information [Line Items]    
Net interest income from external sources 241,317 231,423
Net interest income (expense) from internal sources (67,844) (53,165)
Net interest and dividend income 173,473 178,258
Provision for credit losses 400 148
Net interest income after provision for credit losses 173,073 178,110
Noninterest Income 60,068 55,521
Personnel 51,267 49,574
Other Cost and Expense, Operating 31,041 28,906
Noninterest Expense 82,308 78,480
Corporate Expense Allocations 16,046 17,055
Net income before taxes 134,787 138,096
Assets, Average Outstanding 22,679,465 21,400,745
Operating Segments [Member] | Consumer Banking [Member]    
Segment Reporting Information [Line Items]    
Net interest income from external sources 17,788 8,740
Net interest income (expense) from internal sources 38,201 48,512
Net interest and dividend income 55,989 57,252
Provision for credit losses 1,508 1,517
Net interest income after provision for credit losses 54,481 55,735
Noninterest Income 42,866 39,058
Personnel 25,466 25,837
Other Cost and Expense, Operating 38,027 31,399
Noninterest Expense 63,493 57,236
Corporate Expense Allocations 14,686 15,435
Net income before taxes 19,168 22,122
Assets, Average Outstanding 8,452,393 8,201,821
Operating Segments [Member] | Wealth Management [Member]    
Segment Reporting Information [Line Items]    
Net interest income from external sources 19,867 13,942
Net interest income (expense) from internal sources 23,107 30,560
Net interest and dividend income 42,974 44,502
Provision for credit losses 496 (8)
Net interest income after provision for credit losses 42,478 44,510
Noninterest Income 110,387 96,336
Personnel 69,413 67,245
Other Cost and Expense, Operating 28,756 27,021
Noninterest Expense 98,169 94,266
Corporate Expense Allocations 17,155 13,854
Net income before taxes 37,541 32,726
Assets, Average Outstanding 11,370,683 11,367,435
Funds Management and Other [Member]    
Segment Reporting Information [Line Items]    
Net interest income from external sources 63,582 62,146
Net interest income (expense) from internal sources 6,536 (25,907)
Net interest and dividend income 70,118 36,239
Provision for credit losses (2,404) (1,657)
Net interest income after provision for credit losses 72,522 37,896
Noninterest Income (2,053) (4,874)
Personnel 65,028 71,529
Other Cost and Expense, Operating 45,168 46,018
Noninterest Expense 110,196 117,547
Corporate Expense Allocations (47,887) (46,344)
Net income before taxes 8,160 (38,181)
Assets, Average Outstanding $ 10,620,468 $ 10,016,902