v3.26.1
Reportable Segments (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Segment Reporting [Line Items]        
Net interest income from external sources $ 351,830 $ 328,166 $ 694,384 $ 644,417
Net interest income (expense) from internal sources 0 0 0 0
Net interest and dividend income 351,830 328,166 694,384 644,417
Provision for credit losses 0 0 0 0
Net interest income after provision for credit losses 351,830 328,166 694,384 644,417
Noninterest Income 237,572 207,098 448,840 393,139
Personnel 214,094 214,711 425,268 428,896
Non-personnel expense 147,585 139,792 290,577 273,136
Total other operating expense 361,679 354,503 715,845 702,032
Corporate Expense Allocations 0 0 0 0
Net income before taxes 227,723 180,761 427,379 335,524
Assets, Average Outstanding 54,558,098 52,286,952 53,844,518 51,640,519
Operating Segments [Member]        
Segment Reporting [Line Items]        
Net interest income from external sources 293,858 274,882 572,830 528,987
Net interest income (expense) from internal sources (11,576) 3,902 (18,112) 29,809
Net interest and dividend income 282,282 278,784 554,718 558,796
Provision for credit losses 968 1,040 3,372 2,697
Net interest income after provision for credit losses 281,314 277,744 551,346 556,099
Noninterest Income 203,627 206,247 416,948 397,162
Personnel 141,089 142,171 287,235 284,827
Non-personnel expense 98,636 87,177 196,460 174,502
Total other operating expense 239,725 229,348 483,695 459,329
Corporate Expense Allocations 50,524 49,106 98,411 95,449
Net income before taxes 194,692 205,537 386,188 398,483
Assets, Average Outstanding 43,242,696 41,200,298 42,874,663 41,085,785
Operating Segments [Member] | Commercial Banking [Member]        
Segment Reporting [Line Items]        
Net interest income from external sources 249,695 235,765 491,012 467,188
Net interest income (expense) from internal sources (70,703) (59,939) (138,547) (113,104)
Net interest and dividend income 178,992 175,826 352,465 354,084
Provision for credit losses (145) 29 255 177
Net interest income after provision for credit losses 179,137 175,797 352,210 353,907
Noninterest Income 65,700 64,432 125,768 119,953
Personnel 50,042 50,335 101,309 99,909
Non-personnel expense 32,049 30,256 63,090 59,161
Total other operating expense 82,091 80,591 164,399 159,070
Corporate Expense Allocations 16,586 19,596 32,632 36,650
Net income before taxes 146,160 140,042 280,947 278,140
Assets, Average Outstanding 23,375,564 21,318,236 23,029,437 21,359,263
Operating Segments [Member] | Consumer Banking [Member]        
Segment Reporting [Line Items]        
Net interest income from external sources 18,073 13,463 35,861 22,203
Net interest income (expense) from internal sources 39,839 44,651 78,040 93,163
Net interest and dividend income 57,912 58,114 113,901 115,366
Provision for credit losses 1,118 1,018 2,626 2,535
Net interest income after provision for credit losses 56,794 57,096 111,275 112,831
Noninterest Income 36,823 38,165 79,689 77,223
Personnel 24,715 25,527 50,181 51,364
Non-personnel expense 38,721 29,949 76,748 61,348
Total other operating expense 63,436 55,476 126,929 112,712
Corporate Expense Allocations 16,626 15,039 31,312 30,474
Net income before taxes 13,555 24,746 32,723 46,868
Assets, Average Outstanding 8,648,052 8,310,875 8,550,763 8,256,649
Operating Segments [Member] | Wealth Management [Member]        
Segment Reporting [Line Items]        
Net interest income from external sources 26,090 25,654 45,957 39,596
Net interest income (expense) from internal sources 19,288 19,190 42,395 49,750
Net interest and dividend income 45,378 44,844 88,352 89,346
Provision for credit losses (5) (7) 491 (15)
Net interest income after provision for credit losses 45,383 44,851 87,861 89,361
Noninterest Income 101,104 103,650 211,491 199,986
Personnel 66,332 66,309 135,745 133,554
Non-personnel expense 27,866 26,972 56,622 53,993
Total other operating expense 94,198 93,281 192,367 187,547
Corporate Expense Allocations 17,312 14,471 34,467 28,325
Net income before taxes 34,977 40,749 72,518 73,475
Assets, Average Outstanding 11,219,080 11,571,187 11,294,463 11,469,873
Funds Management and Other [Member]        
Segment Reporting [Line Items]        
Net interest income from external sources 57,972 53,284 121,554 115,430
Net interest income (expense) from internal sources 11,576 (3,902) 18,112 (29,809)
Net interest and dividend income 69,548 49,382 139,666 85,621
Provision for credit losses (968) (1,040) (3,372) (2,697)
Net interest income after provision for credit losses 70,516 50,422 143,038 88,318
Noninterest Income 33,945 851 31,892 (4,023)
Personnel 73,005 72,540 138,033 144,069
Non-personnel expense 48,949 52,615 94,117 98,634
Total other operating expense 121,954 125,155 232,150 242,703
Corporate Expense Allocations (50,524) (49,106) (98,411) (95,449)
Net income before taxes 33,031 (24,776) 41,191 (62,959)
Assets, Average Outstanding $ 11,315,402 $ 11,086,654 $ 10,969,855 $ 10,554,734