Borrowings - Schedule of Available Borrowing Capacity and Related Pledged Collateral (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
Available Borrowing Capacity	$ 3,752,458	$ 3,261,151
Assets Pledged As Collateral
Debt Instrument [Line Items]
Pledged Collateral	4,840,710	4,075,432
FRB Discount Window \| Assets Pledged As Collateral
Debt Instrument [Line Items]
Pledged Collateral	4,040,978	3,245,547
FRB Discount Window \| Assets Pledged As Collateral \| Loans
Debt Instrument [Line Items]
Pledged Collateral		3,200,000
FHLB of Des Moines \| Assets Pledged As Collateral
Debt Instrument [Line Items]
Pledged Collateral	799,732	829,885
FHLB of Des Moines \| Assets Pledged As Collateral \| Loans
Debt Instrument [Line Items]
Pledged Collateral		456,400
FHLB of Des Moines \| Assets Pledged As Collateral \| Securities
Debt Instrument [Line Items]
Pledged Collateral		373,500
FRB Discount Window
Debt Instrument [Line Items]
Available Borrowing Capacity	3,147,467	2,635,034
FRB Discount Window \| FRB Discount Window \| Assets Pledged As Collateral \| Loans
Debt Instrument [Line Items]
Pledged Collateral	4,000,000
FHLB of Des Moines
Debt Instrument [Line Items]
Available Borrowing Capacity	604,991	$ 626,117
FHLB of Des Moines \| FHLB of Des Moines \| Assets Pledged As Collateral \| Loans
Debt Instrument [Line Items]
Pledged Collateral	428,300
FHLB of Des Moines \| FHLB of Des Moines \| Assets Pledged As Collateral \| Securities
Debt Instrument [Line Items]
Pledged Collateral	$ 371,500

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

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The aggregate fair value as of the balance sheet date of financial instruments and other positions owned by the entity including: (1) mortgages, mortgage-backed and asset backed securities; (2) US government and agency obligations; (3) state and municipal government obligations; (4) other sovereign government debt; (5) corporate obligations; (6) corporate equities; (7) principal investments; (8) derivative contracts; and (9) physical commodities. Includes both pledged and unpledged holdings.

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