Capital (Regulatory Capital Requirements) (Details) $ in Millions	Mar. 31, 2026 USD ($)	Dec. 31, 2025 USD ($)
Banking Regulation, Total Capital [Abstract]
Number of Finance Agency Regulatory Capital Requirements	3
Federal Home Loan Bank, Risk-Based Capital, Required	$ 2,063	$ 1,878
Federal Home Loan Bank, Risk-Based Capital, Actual	11,245	10,336
Federal Home Loan Bank, Regulatory Capital, Required	8,089	7,460
Federal Home Loan Bank, Regulatory Capital, Actual	11,245	10,336
Federal Home Loan Bank, Leverage Capital, Required	10,111	9,325
Federal Home Loan Bank, Leverage Capital, Actual	$ 16,866	$ 15,504
Regulatory Capital Ratio, Required	4.00%	4.00%
Federal Home Loan Bank, Regulatory Capital Ratio, Actual	5.56%	5.54%
Federal Home Loan Bank, Capital Stock to Assets, Required	2.00%	2.00%
Federal Home Loan Bank, Capital Stock to Assets, Actual	3.52%	3.38%
Leverage Ratio, Required	5.00%	5.00%
Federal Home Loan Bank, Leverage Ratio, Actual	8.34%	8.31%