Investment Securities Investment Securities (Trading Securities by Major Security Type) (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	$ 843,742	$ 908,608
GSE Debenture [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	241,444	288,438
Non-mortgage-backed securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	241,444	288,438
GSE MBS [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	602,298	620,170
Mortgage-backed securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Trading securities	$ 602,298	$ 620,170