Fair Value - Unfunded Loan and Lease Commitments and Letters of Credit (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Unfunded loan and lease commitments and letters of credit
Aggregate commitments to extend credit, standby letters of credit and commercial letters of credit	$ 7,000,000	$ 7,000,000
Fair Value, Inputs, Level 3 [Member]
Unfunded loan and lease commitments and letters of credit
Aggregate commitments to extend credit, standby letters of credit and commercial letters of credit	7,000,000	7,000,000
Estimated fair value of unfunded loan and lease commitments and letters of credit	$ 52,300	$ 48,500