Fair Value Measurements Carrying Amounts and Estimated Fair Values (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Reported Value Measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, after Allowance for Credit Loss	$ 2,246,526		$ 2,156,694
Cash and due from banks	181,103		192,006
Interest-earning deposits in financial institutions	2,126,862		2,310,206
(amortized cost of $2,646,414 and $2,526,644, respectively)(ACL of $775 and $—, respectively)	2,454,058		2,246,839
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, after Allowance for Credit Loss	2,308,636	[1]	2,306,149
Securities available-for-sale, at fair value	2,454,058
FRB and FHLB stock, at cost	160,442		147,773
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	160,442		147,773
Loans Receivable, Fair Value Disclosure	23,871,794
Warrants and Rights Outstanding			3,763
Equity Securities, FV-NI	2		3
Deposits, Savings Deposits	23,156,094		22,625,485
Time Deposits	4,687,263		4,566,424
Deposits, Fair Value Disclosure	4,684,099		4,556,575
Borrowings (including $113,634 and $118,838 at fair value, respectively)	2,063,819		1,391,814
Long-term Debt, Fair Value	2,069,076		1,382,742
Subordinated debt	952,740		941,923
Subordinated Debt Obligations, Fair Value Disclosure	$ 934,819		$ 901,532
Derivative Liability Statement Of Financial Position Extensible Enumeration Not Disclosed Flag	Interest rate and foreign exchange contracts		Interest rate and foreign exchange contracts
Derivative Liabilities	$ 4,156		$ 7,562
Servicing Rights	17,480		19,623
Debt Securities, Held-to-maturity, Fair Value	2,246,526	[1]	2,156,694
Loans held for sale	182,936		26,331
Loans Held-for-sale, Fair Value Disclosure	183,083		26,562
Interest rate and foreign exchange contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Assets	4,124		7,031
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	181,103		192,006
Interest-earning deposits in financial institutions	2,126,862		2,310,206
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	0		0
Deposits, Savings Deposits	0		0
Deposits, Fair Value Disclosure	0		0
Long-term Debt, Fair Value	275,185		0
Subordinated Debt Obligations, Fair Value Disclosure	0		0
Loans Held-for-sale, Fair Value Disclosure	0		0
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	0		0
Interest-earning deposits in financial institutions	0		0
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	160,442		147,773
Deposits, Savings Deposits	23,156,094		22,625,485
Deposits, Fair Value Disclosure	4,684,099		4,556,575
Long-term Debt, Fair Value	1,680,257		1,263,904
Subordinated Debt Obligations, Fair Value Disclosure	934,819		901,532
Loans Held-for-sale, Fair Value Disclosure	183,083		26,562
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	0		0
Interest-earning deposits in financial institutions	0		0
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	0		0
Loans Receivable, Fair Value Disclosure	23,823,393
Warrants Not Settleable in Cash, Fair Value Disclosure	3,437		3,763	$ 3,689	$ 4,048
Deposits, Savings Deposits	0		0
Deposits, Fair Value Disclosure	0		0
Long-term Debt, Fair Value	113,634		118,838
Subordinated Debt Obligations, Fair Value Disclosure	0		0
Loans Held-for-sale, Fair Value Disclosure	0		0
NonPCI and PCI Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure			22,412,073
NonPCI and PCI Loans [Member] | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	0		0
NonPCI and PCI Loans [Member] | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure	48,401		45,962
NonPCI and PCI Loans [Member] | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure			22,366,111
Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
(amortized cost of $2,646,414 and $2,526,644, respectively)(ACL of $775 and $—, respectively)	2,454,058
Warrants Not Settleable in Cash, Fair Value Disclosure	3,437		3,763
Cash flow hedges in Cash, Fair Value Disclosure, Liabilities	4,065		1,442
Derivative Liability, Fair Value of Collateral	4,156		7,562
Servicing Rights	19,427		21,040
Fair Value, Recurring | Interest rate and foreign exchange contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Fair Value of Collateral	4,124		7,031
Fair Value, Recurring | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
(amortized cost of $2,646,414 and $2,526,644, respectively)(ACL of $775 and $—, respectively)	0		0
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, after Allowance for Credit Loss	185,088		173,283
Equity Securities, FV-NI	2		3
Warrants Not Settleable in Cash, Fair Value Disclosure	0		0
Cash flow hedges in Cash, Fair Value Disclosure, Liabilities	0		0
Derivative Liability, Fair Value of Collateral	0		0
Servicing Rights	0		0
Fair Value, Recurring | Level 1 | Interest rate and foreign exchange contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Fair Value of Collateral	0		0
Fair Value, Recurring | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
(amortized cost of $2,646,414 and $2,526,644, respectively)(ACL of $775 and $—, respectively)	2,451,688		2,244,709
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, after Allowance for Credit Loss	2,057,189		1,976,265
Equity Securities, FV-NI	0		0
Warrants Not Settleable in Cash, Fair Value Disclosure	0		0
Cash flow hedges in Cash, Fair Value Disclosure, Liabilities	4,065		1,442
Derivative Liability, Fair Value of Collateral	4,156		7,562
Servicing Rights	0		0
Fair Value, Recurring | Level 2 | Interest rate and foreign exchange contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Fair Value of Collateral	4,124		7,031
Fair Value, Recurring | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
(amortized cost of $2,646,414 and $2,526,644, respectively)(ACL of $775 and $—, respectively)	2,370		2,130
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, after Allowance for Credit Loss	4,249		7,146
Equity Securities, FV-NI	0		0
Warrants Not Settleable in Cash, Fair Value Disclosure	3,437		3,763
Cash flow hedges in Cash, Fair Value Disclosure, Liabilities	0		0
Derivative Liability, Fair Value of Collateral	0		0
Servicing Rights	19,427		21,040
Fair Value, Recurring | Level 3 | Interest rate and foreign exchange contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Fair Value of Collateral	$ 0		$ 0

[1] Excludes accrued interest receivable of $13.4 million at December 31, 2025 which is recorded in "Other assets" on the consolidated balance shee