Consolidated Obligations (Interest Rate Payment Terms) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Bonds	$ 77,907	$ 71,370
Discount notes, par value	39,155	27,447
Total consolidated obligations, par value	117,062	98,817
Fixed Interest Rate [Member]
Debt Instrument [Line Items]
Bonds	7,623	10,993
Adjustable Interest Rate [Member]
Debt Instrument [Line Items]
Bonds	70,099	60,117
Step-up Interest Rate [Member]
Debt Instrument [Line Items]
Bonds	60	60
Step-down Interest Rate [Member]
Debt Instrument [Line Items]
Bonds	25	100
Range Interest Rate [Member]
Debt Instrument [Line Items]
Bonds	$ 100	$ 100