Loans - Weighted Average Risk Grades for All Commercial Loans by Class (Detail) $ in Thousands |
Mar. 31, 2025
USD ($)
Grade
|
Dec. 31, 2024
USD ($)
Grade
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Loans, net of unearned discounts |
$ 20,903,920
|
$ 20,754,813
|
| Commercial Portfolio Segment [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
6.66
|
6.64
|
| Loans, net of unearned discounts |
$ 6,163,093
|
$ 6,109,532
|
| Commercial and Industrial Total Energy Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
5.64
|
5.58
|
| Loans, net of unearned discounts |
$ 1,153,137
|
$ 1,128,895
|
| Commercial Real Estate Buildings Land And Other Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
7.24
|
7.25
|
| Loans, net of unearned discounts |
$ 7,707,702
|
$ 7,704,447
|
| Construction Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
7.72
|
7.71
|
| Loans, net of unearned discounts |
$ 2,251,265
|
$ 2,264,076
|
| Commercial Real Estate Portfolio Segment [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
7.35
|
7.35
|
| Loans, net of unearned discounts |
$ 9,958,967
|
$ 9,968,523
|
| Risk Grade One To Eight [Member] | Commercial Portfolio Segment [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
6.31
|
6.30
|
| Loans, net of unearned discounts |
$ 5,591,974
|
$ 5,553,757
|
| Risk Grade One To Eight [Member] | Commercial and Industrial Total Energy Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
5.53
|
5.51
|
| Loans, net of unearned discounts |
$ 1,125,772
|
$ 1,111,319
|
| Risk Grade One To Eight [Member] | Commercial Real Estate Buildings Land And Other Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
7.00
|
7.01
|
| Loans, net of unearned discounts |
$ 7,087,996
|
$ 7,103,502
|
| Risk Grade One To Eight [Member] | Construction Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
7.38
|
7.31
|
| Loans, net of unearned discounts |
$ 1,865,357
|
$ 1,860,004
|
| Risk Grade One To Eight [Member] | Commercial Real Estate Portfolio Segment [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
|
7.07
|
| Loans, net of unearned discounts |
|
$ 8,963,506
|
| Risk Grade Nine [Member] | Commercial Portfolio Segment [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
9.00
|
9.00
|
| Loans, net of unearned discounts |
$ 250,436
|
$ 262,446
|
| Risk Grade Nine [Member] | Commercial and Industrial Total Energy Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
9.00
|
9.00
|
| Loans, net of unearned discounts |
$ 11,341
|
$ 11,183
|
| Risk Grade Nine [Member] | Commercial Real Estate Buildings Land And Other Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
9.00
|
9.00
|
| Loans, net of unearned discounts |
$ 231,692
|
$ 211,814
|
| Risk Grade Nine [Member] | Construction Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
9.00
|
9.00
|
| Loans, net of unearned discounts |
$ 244,017
|
$ 171,611
|
| Risk Grade Nine [Member] | Commercial Real Estate Portfolio Segment [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
|
9.00
|
| Loans, net of unearned discounts |
|
$ 383,425
|
| Risk Grade Ten [Member] | Commercial Portfolio Segment [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
10.00
|
10.00
|
| Loans, net of unearned discounts |
$ 134,805
|
$ 88,935
|
| Risk Grade Ten [Member] | Commercial and Industrial Total Energy Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
10.00
|
10.00
|
| Loans, net of unearned discounts |
$ 9,797
|
$ 52
|
| Risk Grade Ten [Member] | Commercial Real Estate Buildings Land And Other Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
10.00
|
10.00
|
| Loans, net of unearned discounts |
$ 201,977
|
$ 173,033
|
| Risk Grade Ten [Member] | Construction Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
10.00
|
10.00
|
| Loans, net of unearned discounts |
$ 141,891
|
$ 232,461
|
| Risk Grade Ten [Member] | Commercial Real Estate Portfolio Segment [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
|
10.00
|
| Loans, net of unearned discounts |
|
$ 405,494
|
| Risk Grade Eleven [Member] | Commercial Portfolio Segment [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
11.00
|
11.00
|
| Loans, net of unearned discounts |
$ 137,027
|
$ 158,390
|
| Risk Grade Eleven [Member] | Commercial and Industrial Total Energy Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
11.00
|
11.00
|
| Loans, net of unearned discounts |
$ 2,192
|
$ 2,262
|
| Risk Grade Eleven [Member] | Commercial Real Estate Buildings Land And Other Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
11.00
|
11.00
|
| Loans, net of unearned discounts |
$ 162,368
|
$ 194,178
|
| Risk Grade Eleven [Member] | Construction Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
11.00
|
11.00
|
| Loans, net of unearned discounts |
$ 0
|
$ 0
|
| Risk Grade Eleven [Member] | Commercial Real Estate Portfolio Segment [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
|
11.00
|
| Loans, net of unearned discounts |
|
$ 194,178
|
| Risk Grade Twelve [Member] | Commercial Portfolio Segment [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
12.00
|
12.00
|
| Loans, net of unearned discounts |
$ 34,427
|
$ 32,739
|
| Risk Grade Twelve [Member] | Commercial and Industrial Total Energy Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
12.00
|
12.00
|
| Loans, net of unearned discounts |
$ 1,358
|
$ 1,379
|
| Risk Grade Twelve [Member] | Commercial Real Estate Buildings Land And Other Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
12.00
|
12.00
|
| Loans, net of unearned discounts |
$ 23,044
|
$ 21,295
|
| Risk Grade Twelve [Member] | Construction Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
12.00
|
12.00
|
| Loans, net of unearned discounts |
$ 0
|
$ 0
|
| Risk Grade Twelve [Member] | Commercial Real Estate Portfolio Segment [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
|
12.00
|
| Loans, net of unearned discounts |
|
$ 21,295
|
| Risk Grade Thirteen [Member] | Commercial Portfolio Segment [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
13.00
|
13.00
|
| Loans, net of unearned discounts |
$ 14,424
|
$ 13,265
|
| Risk Grade Thirteen [Member] | Commercial and Industrial Total Energy Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
13.00
|
13.00
|
| Loans, net of unearned discounts |
$ 2,677
|
$ 2,700
|
| Risk Grade Thirteen [Member] | Commercial Real Estate Buildings Land And Other Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
13.00
|
13.00
|
| Loans, net of unearned discounts |
$ 625
|
$ 625
|
| Risk Grade Thirteen [Member] | Construction Loans [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
13.00
|
13.00
|
| Loans, net of unearned discounts |
$ 0
|
$ 0
|
| Risk Grade Thirteen [Member] | Commercial Real Estate Portfolio Segment [Member] |
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
| Weighted Average Risk Grade | Grade |
|
13.00
|
| Loans, net of unearned discounts |
|
$ 625
|