Borrowings and Subordinated Debentures (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2020
Debt Instrument [Line Items]
Other Borrowings, Fair Value Disclosure	$ 123,116,000	$ 132,030,000
One to Nine Months
Debt Instrument [Line Items]
Assets Sold under Agreements to Repurchase, Interest Rate	8.50%
Ten to 18 months
Debt Instrument [Line Items]
Assets Sold under Agreements to Repurchase, Interest Rate	8.75%
Subordinated notes due May 2031
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.52%
Unused lines of Credit
Debt Instrument [Line Items]
Line of Credit Facility, Amount Outstanding	$ 0
Line of Credit Facility, Current Borrowing Capacity	290,000,000
Debt Instrument, Unused Borrowing Capacity, Fee	0
American Financial Exchange
Debt Instrument [Line Items]
Line of Credit Facility, Amount Outstanding	$ 0	250,000,000
Credit-Link Notes
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	11.00%
Long-term Debt, Percentage Bearing Variable Interest, Amount	$ 132,800,000	132,030,000
Net increase (decrease) in borrowings	128,700,000
Secured Debt	2,480,000,000
Other Borrowings, Fair Value Disclosure	123,116,000	132,030,000	$ 0
Repurchase Agreements
Debt Instrument [Line Items]
Securities Loaned, Fair Value of Collateral	2,100,000,000
Secured Debt, Repurchase Agreements	1,400,000,000
Federal Home Loan Bank of San Francisco
Debt Instrument [Line Items]
Collateralized Financings	9,500,000,000
Securities Loaned, Fair Value of Collateral	20,300,000
Letters of Credit Outstanding, Amount	(243,800,000)
Federal Home Loan Bank of San Francisco | Secured Debt
Debt Instrument [Line Items]
Line of Credit Facility, Borrowing Capacity, Description	5,300,000,000
Line of Credit, Current	0	1,270,000,000
Federal Home Loan Bank of San Francisco | Secured Debt | Bank Term Funding Program
Debt Instrument [Line Items]
Line of Credit, Current	2,618,300,000	0
Federal Home Loan Bank of San Francisco | Unsecured Debt
Debt Instrument [Line Items]
Line of Credit, Current	0	112,000,000
Federal Reserve Bank Advances [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Amount Outstanding	0	$ 0
Federal Reserve Bank Advances [Member] | Secured Debt
Debt Instrument [Line Items]
Line of Credit Facility, Borrowing Capacity, Description	6,900,000,000
Collateralized Financings	7,700,000,000
Securities Loaned, Fair Value of Collateral	1,300,000,000
Federal Reserve Bank Advances [Member] | Secured Debt | Bank Term Funding Program
Debt Instrument [Line Items]
Line of Credit Facility, Borrowing Capacity, Description	2,600,000,000
Securities Loaned, Fair Value of Collateral	$ 2,600,000,000