Commitments And Contingencies (Off-Balance Sheet Commitments) (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Standby letters of credit outstanding [Member]
Loss Contingencies [Line Items]
Fair Value Disclosure, Off Balance Sheet Risks, Face Amount, Expiring Within One Year	$ 6,505,851	$ 7,531,038
Expire After One Year	36,479	11,772
Total	6,542,330	7,542,810
Advance commitments outstanding [Member]
Loss Contingencies [Line Items]
Fair Value Disclosure, Off Balance Sheet Risks, Face Amount, Expiring Within One Year	3,069	3,615
Expire After One Year	2,597	5,115
Total	5,666	8,730
Principal commitments for standby bond purchase agreements [Member]
Loss Contingencies [Line Items]
Fair Value Disclosure, Off Balance Sheet Risks, Face Amount, Expiring Within One Year	199,210	193,815
Expire After One Year	873,680	812,050
Total	1,072,890	1,005,865
Commitments to issue consolidated bonds, at par [Member]
Loss Contingencies [Line Items]
Fair Value Disclosure, Off Balance Sheet Risks, Face Amount, Expiring Within One Year	3,595,000	250,000
Expire After One Year	0	0
Total	3,595,000	250,000
Commitments to issue consolidated obligations discount notes, at par [Member]
Loss Contingencies [Line Items]
Fair Value Disclosure, Off Balance Sheet Risks, Face Amount, Expiring Within One Year	0	200,000
Expire After One Year	0	0
Total	0	200,000
Mortgage Receivable [Member] \| Commitments to fund or purchase mortgage loans [Member]
Loss Contingencies [Line Items]
Fair Value Disclosure, Off Balance Sheet Risks, Face Amount, Expiring Within One Year	86,851	34,524
Expire After One Year	0	0
Total	$ 86,851	$ 34,524