Consolidated Obligations (Interest Rate Payment Terms) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Bonds	$ 71,370	$ 72,336
Discount notes, par value	27,447	29,273
Total consolidated obligations, par value	98,817	101,609
Fixed Interest Rate [Member]
Debt Instrument [Line Items]
Bonds	10,993	16,735
Adjustable Interest Rate [Member]
Debt Instrument [Line Items]
Bonds	60,117	53,668
Step-up Interest Rate [Member]
Debt Instrument [Line Items]
Bonds	60	1,558
Step-down Interest Rate [Member]
Debt Instrument [Line Items]
Bonds	100	275
Range Interest Rate [Member]
Debt Instrument [Line Items]
Bonds	$ 100	$ 100