v3.26.1
Loans and Allowances for Credit Losses (Tables)
 3 Months Ended
Mar. 31, 2026
Loans and Leases Receivable, Net Amount [Abstract]  
Schedule of Loans by Portfolio Segment [Table Text Block]
Portfolio segments of the loan portfolio are as follows (in thousands):
 March 31, 2026December 31, 2025
Fixed
Rate		Variable
Rate		Non-accrualTotalFixed
Rate		Variable
Rate		Non-accrualTotal
Commercial$3,498,856 $12,048,961 $25,266 $15,573,083 $3,494,944 $11,750,021 $36,102 $15,281,067 
Commercial real estate
620,233 5,257,845 6,601 5,884,679 601,044 5,064,265 6,697 5,672,006 
Loans to individuals3,041,701 1,659,793 28,137 4,729,631 3,005,502 1,661,326 31,561 4,698,389 
Total$7,160,790 $18,966,599 $60,004 $26,187,393 $7,101,490 $18,475,612 $74,360 $25,651,462 
Rollforward of Allowance For Loan Losses And Accrual for Off-Balance Sheet Credit Losses [Table Text Block]
The activity in the allowance for loan losses and the allowance for off-balance sheet credit losses related to loan commitments and standby letters of credit is summarized as follows (in thousands):
Three Months Ended
March 31, 2026
 CommercialCommercial Real EstateLoans to IndividualsTotal
Allowance for loan losses:    
Beginning balance$137,225 $86,120 $52,515 $275,860 
Provision for loan losses(875)735 3,872 3,732 
Loans charged off(1,435)— (1,741)(3,176)
Recoveries of loans previously charged off
704 18 581 1,303 
Ending balance$135,619 $86,873 $55,227 $277,719 
Allowance for off-balance sheet credit risk from unfunded loan commitments:
Beginning balance$19,723 $30,086 $1,462 $51,271 
Provision for off-balance sheet credit risk
(1,779)(4,324)169 (5,934)
Ending balance$17,944 $25,762 $1,631 $45,337 
Three Months Ended
March 31, 2025
 CommercialCommercial Real EstateLoans to IndividualsTotal
Allowance for loan losses:    
Beginning balance$145,153 $91,072 $43,810 $280,035 
Provision for loan losses(855)2,467 (1,948)(336)
Loans charged off(1,085)— (1,206)(2,291)
Recoveries of loans previously charged off
292 185 709 1,186 
Ending balance$143,505 $93,724 $41,365 $278,594 
Allowance for off-balance sheet credit risk from unfunded loan commitments:
Beginning balance$18,046 $31,959 $1,635 $51,640 
Provision for off-balance sheet credit risk
(1,879)1,502 825 448 
Ending balance$16,167 $33,461 $2,460 $52,088 
No provision for credit losses was necessary for the first quarter of 2026. The favorable impact of higher projected oil prices on our energy loan portfolio and improved credit quality was offset by loan growth and a slight downward revision to economic forecast assumptions compared to the prior quarter.

The allowance for loan losses and recorded investment of the related loans by portfolio segment for each impairment measurement method at March 31, 2026, is as follows (in thousands):
 Collectively Measured
for General Allowances		Individually Measured
for Specific Allowances		Total
 Recorded InvestmentRelated AllowanceRecorded InvestmentRelated AllowanceRecorded InvestmentRelated
Allowance
Commercial$15,547,817 $132,538 $25,266 $3,081 $15,573,083 $135,619 
Commercial real estate5,878,078 86,873 6,601 — 5,884,679 86,873 
Loans to individuals4,701,494 55,227 28,137 — 4,729,631 55,227 
Total$26,127,389 $274,638 $60,004 $3,081 $26,187,393 $277,719 

The allowance for loan losses and recorded investment of the related loans by portfolio segment for each measurement method at December 31, 2025, is as follows (in thousands):

 Collectively Measured
for General Allowances		Individually Measured
for Specific Allowances		Total
 Recorded InvestmentRelated AllowanceRecorded InvestmentRelated AllowanceRecorded InvestmentRelated
Allowance
Commercial$15,244,965 $133,232 $36,102 $3,993 $15,281,067 $137,225 
Commercial real estate5,665,309 83,925 6,697 2,195 5,672,006 86,120 
Loans to individuals4,666,828 52,515 31,561 — 4,698,389 52,515 
Total$25,577,102 $269,672 $74,360 $6,188 $25,651,462 $275,860 
Schedule of Credit Quality Indicators [Table Text Block]
The following table summarizes the Company’s loan portfolio at March 31, 2026, by the risk grade categories and vintage (in thousands): 
Origination Year
20262025202420232022PriorRevolving LoansRevolving Loans Converted to Term LoansTotal
Commercial:
Healthcare
Pass$155,216 $1,138,937 $472,763 $376,144 $731,332 $687,121 $229,654 $6 $3,791,173 
Special Mention— — — — 9,145 92 4 — 9,241 
Accruing Substandard175 1,493 9,048 37,340 3,761 82,394 — — 134,211 
Nonaccrual— — 1,188 14,850 — 5,100 — — 21,138 
Total healthcare155,391 1,140,430 482,999 428,334 744,238 774,707 229,658 6 3,955,763 
Services
Pass171,749 628,978 420,476 453,455 371,438 799,631 939,073 413 3,785,213 
Special Mention— 980 3,098 1,151 — 21,941 67,320 — 94,490 
Accruing Substandard— 5,783 210 7,118 1,397 5,359 1,103 — 20,970 
Nonaccrual— 393 29 — 838 — — — 1,260 
Total services171,749 636,134 423,813 461,724 373,673 826,931 1,007,496 413 3,901,933 
Loans charged off, year-to-date— — — — — — 1,043 — 1,043 
Energy
Pass30,815 125,973 55,855 43,546 10,128 13,926 2,725,450 — 3,005,693 
Total energy30,815 125,973 55,855 43,546 10,128 13,926 2,725,450 — 3,005,693 
Mortgage finance
Pass— 7,553 — 14,386 — — 206,303 — 228,242 
Total mortgage finance— 7,553 — 14,386 — — 206,303 — 228,242 
General business
Pass192,261 818,635 352,154 322,276 177,623 463,486 2,031,723 1,176 4,359,334 
Special Mention542 15,137 2,334 13,452 3,455 8,574 39,428 156 83,078 
Accruing Substandard3,035 14,789 3,692 5,488 4,452 1,799 2,917 — 36,172 
Nonaccrual— — — — — 2,797 62 9 2,868 
Total general business195,838 848,561 358,180 341,216 185,530 476,656 2,074,130 1,341 4,481,452 
Loans charged off, year-to-date6 — — — — — 386 — 392 
Total commercial553,793 2,758,651 1,320,847 1,289,206 1,313,569 2,092,220 6,243,037 1,760 15,573,083 
Origination Year
20262025202420232022PriorRevolving LoansRevolving Loans Converted to Term LoansTotal
Commercial real estate:
Pass221,026 1,086,536 1,022,175 437,206 1,532,095 1,393,964 109,487 — 5,802,489 
Special Mention— — 1,514 17,219 6,378 2,166 — — 27,277 
Accruing Substandard29 — 482 — 1,065 46,736 — — 48,312 
Nonaccrual— — — — — 6,601 — — 6,601 
Total commercial real estate221,055 1,086,536 1,024,171 454,425 1,539,538 1,449,467 109,487 — 5,884,679 
Loans to individuals:
Residential mortgage
Pass131,859 542,791 378,919 245,780 239,314 706,700 477,756 31,967 2,755,086 
Special Mention— — — 92 137 5,313 803 1,153 7,498 
Accruing Substandard— — — 74 — 27 266 1,008 1,375 
Nonaccrual— 299 1,345 2,514 1,920 8,262 5,099 736 20,175 
Total residential mortgage131,859 543,090 380,264 248,460 241,371 720,302 483,924 34,864 2,784,134 
Loans charged off, year-to-date— — — — — 3 — — 3 
Residential mortgage guaranteed by U.S. government agencies
Pass— 2,210 7,935 12,458 8,617 121,266 — — 152,486 
Nonaccrual— — — — — 7,768 — — 7,768 
Total residential mortgage guaranteed by U.S. government agencies
— 2,210 7,935 12,458 8,617 129,034 — — 160,254 
Personal
Pass65,191 467,124 180,573 189,447 126,524 283,839 465,619 68 1,778,385 
Special Mention— 58 25 4 4 31 1,216 — 1,338 
Accruing Substandard— 5,276 — — — 12 38 — 5,326 
Nonaccrual— — 48 2 8 136 — — 194 
Total personal65,191 472,458 180,646 189,453 126,536 284,018 466,873 68 1,785,243 
Loans charged off, year-to-date1
1,191 18 — 29 1 — 499 — 1,738 
Total loans to individuals197,050 1,017,758 568,845 450,371 376,524 1,133,354 950,797 34,932 4,729,631 
Total loans$971,898 $4,862,945 $2,913,863 $2,194,002 $3,229,631 $4,675,041 $7,303,321 $36,692 $26,187,393 
1    Includes charge-offs on deposit overdrafts, which are generally charged off at 60 days past due.
The following table summarizes the Company's loan portfolio at December 31, 2025, by the risk grade categories and vintage (in thousands): 
Origination Year
20252024202320222021PriorRevolving LoansRevolving Loans Converted to Term LoansTotal
Commercial:
Healthcare
Pass$1,110,851 $460,630 $413,197 $744,765 $298,992 $546,567 $226,298 $9 $3,801,309 
Special Mention— — — 43,576 96 — 5 — 43,677 
Accruing Substandard181 9,589 37,492 4,144 5,170 83,156 — — 139,732 
Nonaccrual— — 14,850 — — 8,638 2 — 23,490 
Total healthcare1,111,032 470,219 465,539 792,485 304,258 638,361 226,305 9 4,008,208 
Loans charged off, year-to-date— — — — 31 — — — 31 
Services
Pass693,147 462,642 488,381 393,685 265,346 612,098 865,163 491 3,780,953 
Special Mention1,071 4,369 428 — — 20,011 76,565 — 102,444 
Accruing Substandard4,595 218 9,857 1,421 2,136 3,404 754 — 22,385 
Nonaccrual446 29 — 864 — — 4,796 — 6,135 
Total services699,259 467,258 498,666 395,970 267,482 635,513 947,278 491 3,911,917 
Loans charged off, year-to-date— — — — — — 4,147 21 4,168 
Energy
Pass147,840 58,798 44,882 10,479 2,297 19,500 2,598,446 — 2,882,242 
Total energy147,840 58,798 44,882 10,479 2,297 19,500 2,598,446 — 2,882,242 
Loans charged off, year-to-date— — — — — — 94 — 94 
Mortgage finance:
Pass— — — — — — 177,765 — 177,765 
Total mortgage finance— — — — — — 177,765 — 177,765 
General business
Pass845,421 389,679 424,859 179,660 139,664 318,834 1,888,938 1,369 4,188,424 
Special Mention24,882 1,480 6,920 4,288 7,070 2,099 40,873 106 87,718 
Accruing Substandard641 4,338 4,416 5,441 1,466 — 2,014 — 18,316 
Nonaccrual— — 1,445 2,163 72 2,787 — 10 6,477 
Total general business870,944 395,497 437,640 191,552 148,272 323,720 1,931,825 1,485 4,300,935 
Loans charged off, year-to-date14 — 132 — — — 826 109 1,081 
Total commercial2,829,075 1,391,772 1,446,727 1,390,486 722,309 1,617,094 5,881,619 1,985 15,281,067 
Origination Year
20252024202320222021PriorRevolving LoansRevolving Loans Converted to Term LoansTotal
Commercial real estate:
Pass948,049 939,354 476,954 1,670,158 671,080 777,510 107,199 — 5,590,304 
Special Mention— — — 6,405 — 3,949 — — 10,354 
Accruing Substandard— 484 — 4,971 29,324 29,872 — — 64,651 
Nonaccrual— — — — — 6,697 — — 6,697 
Total commercial real estate948,049 939,838 476,954 1,681,534 700,404 818,028 107,199 — 5,672,006 
Loans charged off, year-to-date— — — 126 — — — — 126 
Loans to individuals:
Residential mortgage
Pass564,508 404,186 265,734 250,169 280,232 452,195 458,006 29,190 2,704,220 
Special Mention— — — 140 10 5,387 1,628 1,298 8,463 
Accruing Substandard— — 72 — — 12 385 — 469 
Nonaccrual95 1,333 1,314 1,594 1,402 7,280 4,465 780 18,263 
Total residential mortgage564,603 405,519 267,120 251,903 281,644 464,874 464,484 31,268 2,731,415 
Loans charged off, year-to-date— 38 48 — — 56 178 — 320 
Residential mortgage guaranteed by U.S. government agencies
Pass776 3,676 9,453 8,486 2,801 124,581 — — 149,773 
Nonaccrual— — 398 265 — 7,923 — — 8,586 
Total residential mortgage guaranteed by U.S. government agencies
776 3,676 9,851 8,751 2,801 132,504 — — 158,359 
Personal
Pass489,188 188,899 201,427 140,602 101,967 197,075 476,829 282 1,796,269 
Special Mention22 18 46 17 16 4 1,182 — 1,305 
Accruing Substandard6,186 12 — 2 — 129 — — 6,329 
Nonaccrual7 56 4,627 9 12 1 — — 4,712 
Total personal495,403 188,985 206,100 140,630 101,995 197,209 478,011 282 1,808,615 
Loans charged off, year-to-date1
4,325 87 24 19 — 5 25 — 4,485 
Total loans to individuals1,060,782 598,180 483,071 401,284 386,440 794,587 942,495 31,550 4,698,389 
Total loans$4,837,906 $2,929,790 $2,406,752 $3,473,304 $1,809,153 $3,229,709 $6,931,313 $33,535 $25,651,462 
1    Includes charge-offs on deposit overdrafts, which are generally charged off at 60 days past due.
Financing Receivable, Nonaccrual [Table Text Block]
A summary of nonaccruing loans at March 31, 2026, follows (in thousands): 
As of March 31, 2026
 TotalWith No
Allowance		With AllowanceRelated Allowance
Commercial:    
Healthcare$21,138 $14,850 $6,288 $331 
Services1,260 1,260 — — 
General business2,868 118 2,750 2,750 
Total commercial25,266 16,228 9,038 3,081 
Commercial real estate6,601 6,601 — — 
Loans to individuals:    
Residential mortgage20,175 20,175 — — 
Residential mortgage guaranteed by U.S. government agencies7,768 7,768 — — 
Personal194 194 — — 
Total loans to individuals28,137 28,137 — — 
Total$60,004 $50,966 $9,038 $3,081 

The majority of our nonaccruing loans are considered collateral dependent where repayment is expected to be provided through operation or sale of the collateral. Nonaccruing commercial and commercial real estate loans are primarily secured by commercial real estate and nonaccruing residential mortgage loans are secured by residential real estate.

A summary of nonaccruing loans at December 31, 2025, follows (in thousands): 
As of December 31, 2025
 TotalWith No
Allowance		With AllowanceRelated Allowance
Commercial:    
Healthcare$23,490 $18,390 $5,100 $200 
Services6,135 1,339 4,796 1,043 
General business6,477 3,727 2,750 2,750 
Total commercial36,102 23,456 12,646 3,993 
Commercial real estate6,697 — 6,697 2,195 
Loans to individuals:    
Residential mortgage18,263 18,263 — — 
Residential mortgage guaranteed by U.S. government agencies8,586 8,586 — — 
Personal4,712 4,712 — — 
Total loans to individuals31,561 31,561 — — 
Total$74,360 $55,017 $19,343 $6,188 
Summary of Loans by Aging Status [Table Text Block]
A summary of loans currently performing and past due as of March 31, 2026, is as follows (in thousands):
  Past Due Past Due 90 Days or More and Accruing
 Current30 to 59
Days		60 to 89 Days90 Days
or More		Total
Commercial:    
Healthcare$3,935,813 $— $— $19,950 $3,955,763 $— 
Services3,901,776 100 28 29 3,901,933 — 
Energy3,005,693 — — — 3,005,693 — 
Mortgage finance228,242 — — — 228,242 — 
General business4,474,908 1,450 247 4,847 4,481,452 2,097 
Total commercial15,546,432 1,550 275 24,826 15,573,083 2,097 
Commercial real estate5,878,078 — — 6,601 5,884,679 — 
Loans to individuals:    
Residential mortgage2,761,898 16,182 843 5,211 2,784,134 314 
Residential mortgage guaranteed by U.S. government agencies48,337 27,087 — 84,830 160,254 81,958 
Personal1,782,318 1,339 1,460 126 1,785,243 — 
Total loans to individuals4,592,553 44,608 2,303 90,167 4,729,631 82,272 
Total$26,017,063 $46,158 $2,578 $121,594 $26,187,393 $84,369 
A summary of loans currently performing and past due as of December 31, 2025, is as follows (in thousands):
  Past Due Past Due 90 Days or More and Accruing
 Current30 to 59
Days		60 to 89 Days90 Days
or More		Total
Commercial:    
Healthcare$3,984,720 $— $— $23,488 $4,008,208 $— 
Services3,903,616 3,476 4,796 29 3,911,917 — 
Energy2,882,242 — — — 2,882,242 — 
Mortgage finance177,765 — — — 177,765 — 
General business4,291,391 5,702 3,842 — 4,300,935 — 
Total commercial15,239,734 9,178 8,638 23,517 15,281,067 — 
Commercial real estate5,664,492 817 — 6,697 5,672,006 — 
Loans to individuals:    
Residential mortgage2,714,617 8,570 2,182 6,046 2,731,415 — 
Residential mortgage guaranteed by U.S. government agencies
47,950 17,975 11,377 81,057 158,359 76,535 
Personal1,799,975 3,463 551 4,626 1,808,615 — 
Total loans to individuals4,562,542 30,008 14,110 91,729 4,698,389 76,535 
Total$25,466,768 $40,003 $22,748 $121,943 $25,651,462 $76,535