Segment Reporting (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Interest Income (Expense), Operating	$ 1,047,248	$ 1,039,573	$ 957,321
Noninterest Income	(9,407)	63,182	282,370
Provision for Loan, Lease, and Other Losses	84,986	83,021	32,998
Interest Income (Expense), after Provision for Loan Loss	962,263	956,552	924,323
Labor and Related Expense	487,956	468,355	454,101
Information Technology and Data Processing	107,563	102,018	90,700
Occupancy, Net	54,622	57,204	59,794
Marketing and Advertising Expense	28,142	28,405	25,525
Equipment Expense	18,431	19,663	19,632
Professional Fees	21,601	19,911	18,250
Payments of Financing Costs	8,471	5,408	5,925
Federal Deposit Insurance Corporation Premium Expense	38,439	67,072	22,650
Amortization of Intangible Assets	8,811	8,811	8,811
FHLB Advances, Prepayment Penalty	14,243
Other Noninterest Expense	30,118	36,837	41,675
Noninterest Expense	818,397	813,682	747,063
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	134,459	206,052	459,630
Income Tax Expense (Benefit)	11,314	23,097	93,508
Net Income (Loss)	123,145	182,956	366,122
Loans and Leases Receivable, Net of Deferred Income	29,768,586	29,216,218
Goodwill	1,104,992	1,104,992
Assets	43,023,068	41,015,855
Gain (Loss) on Sale of Mortgage Loans_narrative	(130,000)	(136,000)
Gain (Loss) on Sale of Investments	148,000	65,000
FDIC Special Assessment		31,000
Corporate and Commercial Specialty [Member]
Segment Reporting Information [Line Items]
A portion of total depreciation Technology expense	242	164	15
Community, Consumer and Business [Member]
Segment Reporting Information [Line Items]
A portion of total depreciation Occupancy expense	10,000	8,000	4,000
Risk Management and Shared Services [Member]
Segment Reporting Information [Line Items]
A portion of total depreciation Equipment expense	39,000	39,000	41,000
Operating Segments [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Operating	1,047,248	1,039,573	957,321
Net intersegment interest income (expense)	0	0	0
Segment net interest income	1,047,248	1,039,573	957,321
Noninterest Income	(9,407)	63,182	282,370
Interest income (expense) before provision	1,037,841	1,102,756	1,239,691
Provision for Loan, Lease, and Other Losses	84,986	83,021	32,998
Interest Income (Expense), after Provision for Loan Loss	952,855	1,019,734	1,206,693
Labor and Related Expense	487,956	468,355	454,101
Information Technology and Data Processing	107,563	102,018	90,700
Occupancy, Net	54,622	57,204	59,794
Marketing and Advertising Expense	28,142	28,405	25,525
Equipment Expense	18,431	19,663	19,632
Professional Fees	21,601	19,911	18,250
Payments of Financing Costs	8,471	5,408	5,925
Federal Deposit Insurance Corporation Premium Expense	38,439	67,072	22,650
Amortization of Intangible Assets	8,811	8,811	8,811
FHLB Advances, Prepayment Penalty	14,243
Other Noninterest Expense	30,118	36,837	41,675
Allocated indirect expense	0	0	0
Noninterest Expense	818,397	813,682	747,063
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	134,459	206,052	459,630
Income Tax Expense (Benefit)	11,314	23,097	93,508
Net Income (Loss)	123,145	182,956	366,122
Loans and Leases Receivable, Net of Deferred Income	29,768,586	29,216,218	28,799,569
Goodwill	1,104,992	1,104,992	1,104,992
Assets	43,023,068	41,015,855	39,405,727
Operating Segments [Member] | Corporate and Commercial Specialty [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Operating	976,878	933,929	526,870
Net intersegment interest income (expense)	(429,917)	(432,073)	(118,059)
Segment net interest income	546,961	501,856	408,811
Noninterest Income	53,435	51,905	58,938
Interest income (expense) before provision	600,396	553,761	467,749
Provision for Loan, Lease, and Other Losses	66,390	54,302	47,939
Interest Income (Expense), after Provision for Loan Loss	534,006	499,459	419,810
Labor and Related Expense	79,853	71,688	71,043
Information Technology and Data Processing	2,594	2,931	3,029
Occupancy, Net	0	0	0
Marketing and Advertising Expense	3,543	4,042	3,703
Equipment Expense	2	1	1
Professional Fees	825	1,359	1,025
Payments of Financing Costs	1,100	877	528
Federal Deposit Insurance Corporation Premium Expense	0	0	0
Amortization of Intangible Assets	0	0	0
FHLB Advances, Prepayment Penalty	0
Other Noninterest Expense	3,338	3,501	3,350
Allocated indirect expense	88,036	83,190	73,548
Noninterest Expense	179,291	167,589	156,227
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	354,715	331,870	263,583
Income Tax Expense (Benefit)	64,346	59,143	47,440
Net Income (Loss)	290,369	272,727	216,143
Loans and Leases Receivable, Net of Deferred Income	16,959,921	16,045,897	17,083,254
Goodwill	525,836	525,836	525,836
Assets	17,794,372	16,897,021	17,909,477
Operating Segments [Member] | Community, Consumer and Business [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Operating	247,791	309,291	362,420
Net intersegment interest income (expense)	579,587	487,897	190,862
Segment net interest income	827,378	797,188	553,282
Noninterest Income	198,485	193,948	205,660
Interest income (expense) before provision	1,025,863	991,136	758,942
Provision for Loan, Lease, and Other Losses	24,759	29,757	22,359
Interest Income (Expense), after Provision for Loan Loss	1,001,104	961,379	736,583
Labor and Related Expense	232,787	236,385	238,962
Information Technology and Data Processing	47,241	44,661	33,330
Occupancy, Net	61	95	82
Marketing and Advertising Expense	3,169	4,001	3,428
Equipment Expense	5,930	5,770	5,365
Professional Fees	1,978	1,933	4,209
Payments of Financing Costs	5,018	3,065	4,308
Federal Deposit Insurance Corporation Premium Expense	0	0	0
Amortization of Intangible Assets	0	0	0
FHLB Advances, Prepayment Penalty	0
Other Noninterest Expense	27,921	29,800	31,720
Allocated indirect expense	205,979	191,613	173,645
Noninterest Expense	530,084	517,323	495,049
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	471,020	444,056	241,534
Income Tax Expense (Benefit)	97,460	91,770	49,347
Net Income (Loss)	373,560	352,286	192,187
Loans and Leases Receivable, Net of Deferred Income	12,318,648	12,642,123	11,231,404
Goodwill	579,156	579,156	579,156
Assets	13,892,891	13,453,475	12,073,694
Operating Segments [Member] | Risk Management and Shared Services [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Operating	(177,421)	(203,647)	68,031
Net intersegment interest income (expense)	(149,670)	(55,824)	(72,803)
Segment net interest income	(327,091)	(259,471)	(4,772)
Noninterest Income	(261,327)	(182,671)	17,772
Interest income (expense) before provision	(588,418)	(442,142)	12,999
Provision for Loan, Lease, and Other Losses	(6,163)	(1,038)	(37,300)
Interest Income (Expense), after Provision for Loan Loss	(582,255)	(441,104)	50,299
Labor and Related Expense	175,316	160,282	144,096
Information Technology and Data Processing	57,728	54,426	54,341
Occupancy, Net	54,561	57,109	59,712
Marketing and Advertising Expense	21,430	20,362	18,394
Equipment Expense	12,499	13,892	14,266
Professional Fees	18,798	16,619	13,016
Payments of Financing Costs	2,353	1,466	1,089
Federal Deposit Insurance Corporation Premium Expense	38,439	67,072	22,650
Amortization of Intangible Assets	8,811	8,811	8,811
FHLB Advances, Prepayment Penalty	14,243
Other Noninterest Expense	(1,141)	3,534	6,605
Allocated indirect expense	(294,015)	(274,803)	(247,193)
Noninterest Expense	109,022	128,770	95,787
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	(691,277)	(569,873)	(45,488)
Income Tax Expense (Benefit)	(150,492)	(127,816)	(3,279)
Net Income (Loss)	(540,785)	(442,057)	(42,209)
Loans and Leases Receivable, Net of Deferred Income	490,017	528,198	484,911
Goodwill	0	0	0
Assets	$ 11,335,805	$ 10,665,359	$ 9,422,556