Fair Value Measurements Carrying Amounts and Estimated Fair Values (Details) - USD ($) $ in Thousands		Dec. 31, 2023		Dec. 31, 2022	Dec. 31, 2021
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		$ 202,427		$ 212,273
Interest-earning deposits in financial institutions		5,175,149		2,027,949
(amortized cost of $2,699,255 and $5,654,617, respectively)		2,346,864		4,843,487
(fair value of $2,168,316 and $2,110,472, respectively)		2,287,291	[1]	2,269,135
Securities available-for-sale, at fair value		2,346,864
FRB and FHLB stock, at cost		126,346		34,290
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure		126,346		34,290
Loans and leases, net	[2]	25,208,000		28,408,397
Loans Receivable, Fair Value Disclosure		23,551,725
Warrants and Rights Outstanding				4,048
Derivative Assets		12,178		11,862
Equity Securities, FV-NI		1		1
Deposits, Savings Deposits		23,768,896		29,198,491
Time Deposits		6,632,873		4,737,843
Deposits, Fair Value Disclosure		6,732,246		4,700,054
Long-Term Debt		2,911,322		1,764,030
Long-term Debt, Fair Value		2,908,527		1,764,037
Subordinated debt		936,599		867,087
Subordinated Debt Obligations, Fair Value Disclosure		851,625		870,534
Derivative Liabilities		10,549		5,906
Servicing Rights		22,174		633
Debt Securities, Held-to-maturity, Fair Value		2,168,316	[1]	2,110,472
Loans held for sale		122,757		65,076
Loans Held-for-sale, Fair Value Disclosure		126,646		65,501
Reported Value Measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
(fair value of $2,168,316 and $2,110,472, respectively)		2,168,316		2,110,472
Interest rate and economic contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Assets		8,309		7,814
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks		202,427		212,273
Interest-earning deposits in financial institutions		5,175,149		2,027,949
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		0		882,000
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		126,346		34,290
Deposits, Savings Deposits		23,768,896		29,198,491
Deposits, Fair Value Disclosure		6,732,246		4,700,054
Long-term Debt, Fair Value		2,785,411		750,007
Subordinated Debt Obligations, Fair Value Disclosure		851,625		870,534
Loans Held-for-sale, Fair Value Disclosure		126,646		65,501
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		23,547,674
Warrants Not Settleable in Cash, Fair Value Disclosure				4,048	$ 3,555
Deposits, Savings Deposits		0		0
Deposits, Fair Value Disclosure		0		0
Long-term Debt, Fair Value		123,116		132,030
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				26,627,985
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		4,051		28,065
NonPCI and PCI Loans [Member] | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Receivable, Fair Value Disclosure				26,599,920
Fair Value, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
(amortized cost of $2,699,255 and $5,654,617, respectively)		2,346,864
Warrants Not Settleable in Cash, Fair Value Disclosure		3,689		4,048
Derivative Liability, Fair Value of Collateral		10,549		5,906
Fair Value, Recurring | Interest rate and economic contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Fair Value of Collateral		8,309		7,814
Fair Value, Recurring | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
(amortized cost of $2,699,255 and $5,654,617, respectively)		4,968		670,070
(fair value of $2,168,316 and $2,110,472, respectively)		175,579		171,700
Equity Securities, FV-NI		1		1
Warrants Not Settleable in Cash, Fair Value Disclosure		0		0
Derivative Liability, Fair Value of Collateral		0		0
Servicing Rights		0		0
Fair Value, Recurring | Level 1 | Interest rate and economic 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 $2,699,255 and $5,654,617, respectively)		2,301,647		4,173,417
(fair value of $2,168,316 and $2,110,472, respectively)		1,976,015		1,938,772
Equity Securities, FV-NI		0		0
Warrants Not Settleable in Cash, Fair Value Disclosure		0		0
Derivative Liability, Fair Value of Collateral		10,549		5,906
Servicing Rights		0		0
Fair Value, Recurring | Level 2 | Interest rate and economic contracts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Asset, Fair Value of Collateral		8,309		7,814
Fair Value, Recurring | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
(amortized cost of $2,699,255 and $5,654,617, respectively)		40,249		0
(fair value of $2,168,316 and $2,110,472, respectively)		16,722		0
Equity Securities, FV-NI		0		0
Warrants Not Settleable in Cash, Fair Value Disclosure		3,689		4,048
Derivative Liability, Fair Value of Collateral		0		0
Servicing Rights		22,174		633
Fair Value, Recurring | Level 3 | Interest rate and economic 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, 2023 which is recorded in "Other assets" on the consolidated balance shee

[2] Excludes accrued interest receivable of $111.3 million and $124.3 million at December 31, 2023 and 2022, which is recorded in "Other assets" on the consolidated balance sheets.