Fair Value (Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions | Sep. 30, 2024 | Dec. 31, 2023 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | $ 4,131 | $ 3,152 |
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset | 1,032 | 975 |
Derivative assets, net | 1,437 | 1,267 |
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset | 52 | 94 |
Derivative liabilities, net | (6) | (7) |
Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 0 | 0 |
Debt Securities, Available-for-sale | 0 | 0 |
Derivative assets, net | 0 | 0 |
Other assets | 44 | 39 |
Derivative liabilities, net | 0 | 0 |
Mortgage loans held for portfolio, net | 0 | 0 |
Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 4,131 | 3,152 |
Debt Securities, Available-for-sale | 24,634 | 23,823 |
Derivative assets, net | 405 | 292 |
Other assets | 0 | 0 |
Derivative liabilities, net | (58) | (101) |
Mortgage loans held for portfolio, net | 10,604 | 9,051 |
Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 0 | 0 |
Debt Securities, Available-for-sale | 0 | 0 |
Derivative assets, net | 0 | 0 |
Other assets | 0 | 0 |
Derivative liabilities, net | 0 | 0 |
Mortgage loans held for portfolio, net | 33 | 30 |
Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset | 1,032 | 975 |
Derivative assets, net | 1,437 | 1,267 |
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset | 52 | 94 |
Fair Value, Recurring [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 0 | 0 |
Debt Securities, Available-for-sale | 0 | 0 |
Derivative assets, net | 0 | 0 |
Other assets | 44 | 39 |
Total recurring assets | 44 | 39 |
Derivative liabilities, net | 0 | 0 |
Total recurring liabilities | 0 | 0 |
Fair Value, Recurring [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 4,131 | 3,152 |
Debt Securities, Available-for-sale | 24,634 | 23,823 |
Derivative assets, net | 405 | 292 |
Other assets | 0 | 0 |
Total recurring assets | 29,170 | 27,267 |
Derivative liabilities, net | (58) | (101) |
Total recurring liabilities | (50,399) | (47,543) |
Fair Value, Recurring [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 0 | 0 |
Debt Securities, Available-for-sale | 0 | 0 |
Derivative assets, net | 0 | 0 |
Other assets | 0 | 0 |
Total recurring assets | 0 | 0 |
Derivative liabilities, net | 0 | 0 |
Total recurring liabilities | 0 | 0 |
Fair Value, Nonrecurring [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Total recurring assets | 0 | 0 |
Mortgage loans held for portfolio, net | 0 | 0 |
Fair Value, Nonrecurring [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Total recurring assets | 0 | 0 |
Mortgage loans held for portfolio, net | 0 | 0 |
Fair Value, Nonrecurring [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Total recurring assets | 4 | 1 |
Mortgage loans held for portfolio, net | 4 | 1 |
Interest Rate Swap [Member] | Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset | 1,032 | 975 |
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset | 52 | 94 |
Interest Rate Swap [Member] | Fair Value, Recurring [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative assets, net | 0 | 0 |
Derivative liabilities, net | 0 | 0 |
Interest Rate Swap [Member] | Fair Value, Recurring [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative assets, net | 404 | 291 |
Derivative liabilities, net | (57) | (100) |
Interest Rate Swap [Member] | Fair Value, Recurring [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative assets, net | 0 | 0 |
Derivative liabilities, net | 0 | 0 |
Forward Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative assets, net | 0 | |
Derivative liabilities, net | | 0 |
Forward Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative assets, net | 1 | |
Derivative liabilities, net | | (1) |
Forward Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative assets, net | 0 | |
Derivative liabilities, net | | 0 |
Fair Value [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 4,131 | 3,152 |
Debt Securities, Available-for-sale | 24,634 | 23,823 |
Derivative assets, net | 1,437 | 1,267 |
Other assets | 44 | 39 |
Derivative liabilities, net | (6) | (7) |
Mortgage loans held for portfolio, net | 10,637 | 9,081 |
Fair Value [Member] | Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 4,131 | 3,152 |
Debt Securities, Available-for-sale | 24,634 | 23,823 |
Other assets | 44 | 39 |
Total recurring assets | 30,246 | 28,281 |
Derivative liabilities, net | (6) | (7) |
Total recurring liabilities | (50,347) | (47,449) |
Fair Value [Member] | Fair Value, Nonrecurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Total recurring assets | 4 | 1 |
Mortgage loans held for portfolio, net | 4 | 1 |
Fair Value [Member] | Interest Rate Swap [Member] | Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative assets, net | 1,436 | 1,266 |
Derivative liabilities, net | (5) | (6) |
Fair Value [Member] | Forward Contracts [Member] | Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative assets, net | 1 | |
Derivative liabilities, net | | (1) |
Consolidated Obligation Discount Notes [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Discount notes | 0 | 0 |
Consolidated Obligation Discount Notes [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Discount notes | 59,470 | 54,534 |
Consolidated Obligation Discount Notes [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Discount notes | 0 | 0 |
Consolidated Obligation Discount Notes [Member] | Fair Value, Recurring [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Discount notes | 0 | 0 |
Consolidated Obligation Discount Notes [Member] | Fair Value, Recurring [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Discount notes | (50,341) | 47,442 |
Consolidated Obligation Discount Notes [Member] | Fair Value, Recurring [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Discount notes | 0 | 0 |
Consolidated Obligation Discount Notes [Member] | Fair Value [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Discount notes | 59,470 | 54,534 |
US Treasury Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 3,913 | 2,925 |
US Treasury Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 0 | 0 |
US Treasury Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 3,913 | 2,925 |
US Treasury Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 0 | 0 |
US Treasury Securities [Member] | Fair Value [Member] | Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 3,913 | 2,925 |
U.S. obligations [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 61 | 68 |
U.S. obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 0 | 0 |
Debt Securities, Available-for-sale | 0 | 0 |
U.S. obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 61 | 68 |
Debt Securities, Available-for-sale | 166 | 328 |
U.S. obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 0 | 0 |
Debt Securities, Available-for-sale | 0 | 0 |
U.S. obligations [Member] | Fair Value [Member] | Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 61 | 68 |
Debt Securities, Available-for-sale | 166 | 328 |
GSE obligations [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 49 | 49 |
GSE obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 0 | 0 |
Debt Securities, Available-for-sale | 0 | 0 |
GSE obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 49 | 49 |
Debt Securities, Available-for-sale | 329 | 344 |
GSE obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 0 | 0 |
Debt Securities, Available-for-sale | 0 | 0 |
GSE obligations [Member] | Fair Value [Member] | Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 49 | 49 |
Debt Securities, Available-for-sale | 329 | 344 |
State or local housing agency obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 0 | 0 |
State or local housing agency obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 524 | 458 |
State or local housing agency obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 0 | 0 |
State or local housing agency obligations [Member] | Fair Value [Member] | Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 524 | 458 |
Other [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 108 | 110 |
Other [Member] | Fair Value, Recurring [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 0 | 0 |
Debt Securities, Available-for-sale | 0 | 0 |
Other [Member] | Fair Value, Recurring [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 108 | 110 |
Debt Securities, Available-for-sale | 48 | 160 |
Other [Member] | Fair Value, Recurring [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 0 | 0 |
Debt Securities, Available-for-sale | 0 | 0 |
Other [Member] | Fair Value [Member] | Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Trading securities | 108 | 110 |
Debt Securities, Available-for-sale | 48 | 160 |
U.S. obligations MBS [Member] | Single Family [Member] | Fair Value, Recurring [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 0 | 0 |
U.S. obligations MBS [Member] | Single Family [Member] | Fair Value, Recurring [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 4,716 | 4,398 |
U.S. obligations MBS [Member] | Single Family [Member] | Fair Value, Recurring [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 0 | 0 |
U.S. obligations MBS [Member] | Single Family [Member] | Fair Value [Member] | Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 4,716 | 4,398 |
Mortgage-backed securities, GSE [Member] | Single Family [Member] | Fair Value, Recurring [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 0 | 0 |
Mortgage-backed securities, GSE [Member] | Single Family [Member] | Fair Value, Recurring [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 204 | 180 |
Mortgage-backed securities, GSE [Member] | Single Family [Member] | Fair Value, Recurring [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 0 | 0 |
Mortgage-backed securities, GSE [Member] | Single Family [Member] | Fair Value [Member] | Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 204 | 180 |
Mortgage-backed securities, GSE [Member] | Multifamily [Member] | Fair Value, Recurring [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 0 | 0 |
Mortgage-backed securities, GSE [Member] | Multifamily [Member] | Fair Value, Recurring [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 18,647 | 17,955 |
Mortgage-backed securities, GSE [Member] | Multifamily [Member] | Fair Value, Recurring [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 0 | 0 |
Mortgage-backed securities, GSE [Member] | Multifamily [Member] | Fair Value [Member] | Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Debt Securities, Available-for-sale | 18,647 | 17,955 |
Mortgages [Member] | Forward Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative assets, net | | 0 |
Derivative liabilities, net | 0 | |
Mortgages [Member] | Forward Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative assets, net | | 1 |
Derivative liabilities, net | (1) | |
Mortgages [Member] | Forward Contracts [Member] | Fair Value, Recurring [Member] | Fair Value, Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative assets, net | | 0 |
Derivative liabilities, net | 0 | |
Mortgages [Member] | Fair Value [Member] | Forward Contracts [Member] | Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivative assets, net | | 1 |
Derivative liabilities, net | (1) | |
Fair Value Option Election | Consolidated Obligation Discount Notes [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Discount notes | (50,341) | (47,442) |
Fair Value Option Election | Consolidated Obligation Discount Notes [Member] | Fair Value, Recurring [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Discount notes | $ (50,341) | $ 47,442 |