Advances by Current Interest Rate Terms (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Federal Home Loan Bank, Advances, Fixed Rate [Abstract]
Fixed-rate	$ 35,460,466	$ 28,106,591
Federal Home Loan Bank, Advances, Floating Rate [Abstract]
Variable-rate	9,455,936	6,477,296
Total par value	$ 44,916,402	$ 34,583,887