Loans and Allowance for Credit Losses (Credit Quality Indicators by Segment and Portfolio Class) (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Total Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 17,968,274	$ 18,589,081
Total Commercial [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	12,888,547	13,051,047
Total Commercial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	16,823,845	17,881,759
Total Commercial [Member] | Pass [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	11,990,460	12,540,295
Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	521,400	433,630
Total Commercial [Member] | Pass-Watch [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	355,541	286,238
Total Commercial [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	190,898	59,315
Total Commercial [Member] | Special Mention [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	167,606	18,133
Total Commercial [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	432,131	214,377
Total Commercial [Member] | Substandard [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	374,940	206,381
Residential Mortgages [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,961,328	3,886,072
Residential Mortgages [Member] | Performing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,917,242	3,859,935
Residential Mortgages [Member] | Nonperforming [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	44,086	26,137
Consumer [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,369,845	1,446,764
Consumer [Member] | Performing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,358,658	1,438,209
Consumer [Member] | Nonperforming [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	11,187	8,555
Residential Mortgage and Consumer [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	5,331,173	5,332,836
Residential Mortgage and Consumer [Member] | Performing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	5,275,900	5,298,144
Residential Mortgage and Consumer [Member] | Nonperforming [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	55,273	34,692
Commercial Non-Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	9,876,592	9,957,284
Commercial Non-Real Estate [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	9,157,232	9,524,018
Commercial Non-Real Estate [Member] | Pass-Watch [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	219,975	234,211
Commercial Non-Real Estate [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	149,705	11,486
Commercial Non-Real Estate [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	349,680	187,569
Commercial Non-Real Estate [Member] | Total Commercial [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	9,876,592	9,957,284
Commercial Non-Real Estate [Member] | Total Commercial [Member] | Pass [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	9,157,232	9,524,018
Commercial Non-Real Estate [Member] | Total Commercial [Member] | Pass-Watch [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	219,975	234,211
Commercial Non-Real Estate [Member] | Total Commercial [Member] | Special Mention [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	149,705	11,486
Commercial Non-Real Estate [Member] | Total Commercial [Member] | Substandard [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	349,680	187,569
Commercial Real Estate - Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,011,955	3,093,763
Commercial Real Estate - Owner Occupied [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,833,228	3,016,277
Commercial Real Estate - Owner Occupied [Member] | Pass-Watch [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	135,566	52,027
Commercial Real Estate - Owner Occupied [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	17,901	6,647
Commercial Real Estate - Owner Occupied [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	25,260	18,812
Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,011,955	3,093,763
Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Pass [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,833,228	3,016,277
Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Pass-Watch [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	135,566	52,027
Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Special Mention [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	17,901	6,647
Commercial Real Estate - Owner Occupied [Member] | Total Commercial [Member] | Substandard [Member] | Total Commercial And Industrial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	25,260	18,812
Commercial Real Estate - Income Producing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,798,612	3,986,943
Commercial Real Estate - Income Producing [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,625,981	3,799,004
Commercial Real Estate - Income Producing [Member] | Pass-Watch [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	99,638	139,932
Commercial Real Estate - Income Producing [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	22,278	40,826
Commercial Real Estate - Income Producing [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	50,715	7,181
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,798,612	3,986,943
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	3,625,981	3,799,004
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	99,638	139,932
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	22,278	40,826
Commercial Real Estate - Income Producing [Member] | Total Commercial [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	50,715	7,181
Construction and Land Development [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,281,115	1,551,091
Construction and Land Development [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,207,404	1,542,460
Construction and Land Development [Member] | Pass-Watch [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	66,221	7,460
Construction and Land Development [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,014	356
Construction and Land Development [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	6,476	815
Construction and Land Development [Member] | Total Commercial [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,281,115	1,551,091
Construction and Land Development [Member] | Total Commercial [Member] | Pass [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,207,404	1,542,460
Construction and Land Development [Member] | Total Commercial [Member] | Pass-Watch [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	66,221	7,460
Construction and Land Development [Member] | Total Commercial [Member] | Special Mention [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	1,014	356
Construction and Land Development [Member] | Total Commercial [Member] | Substandard [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 6,476	$ 815