v3.26.1
Investments AFS - Schedule of Reconciliation Table (Details) - USD ($)
Jun. 30, 2026
Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]    
AFS Securities - Amortized Cost, $ 20,573,450,000 $ 18,171,361,000 [1]
Balance, beginning of period 18,959,000 16,713,000
Gross Unrealized Gains 90,062,000 82,027,000
Gross Unrealized Losses (48,625,000) (47,348,000)
Available-for-Sale - Accrued Interest 66,400,000 59,100,000
Fair Value $ 20,595,928,000 $ 18,189,327,000
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] Accrued interest receivable Accrued interest receivable
GSE obligations    
Debt Securities, Available-for-sale [Line Items]    
AFS Securities - Amortized Cost, [1] $ 761,901,000 $ 817,747,000
Balance, beginning of period 0 0
Gross Unrealized Gains 14,859,000 17,326,000
Gross Unrealized Losses (1,195,000) (1,010,000)
Fair Value 775,565,000 834,063,000
State or local agency obligations [Member]    
Debt Securities, Available-for-sale [Line Items]    
AFS Securities - Amortized Cost, [1] 182,560,000 181,516,000
Balance, beginning of period 0 0
Gross Unrealized Gains 5,000 10,000
Gross Unrealized Losses (6,663,000) (6,693,000)
Fair Value 175,902,000 174,833,000
Non-MBS [Member]    
Debt Securities, Available-for-sale [Line Items]    
AFS Securities - Amortized Cost, [1] 6,044,853,000 5,902,065,000
Balance, beginning of period 0 0
Gross Unrealized Gains 21,288,000 27,085,000
Gross Unrealized Losses (9,196,000) (7,974,000)
Fair Value 6,056,945,000 5,921,176,000
U.S. obligations single-family    
Debt Securities, Available-for-sale [Line Items]    
AFS Securities - Amortized Cost, [1] 1,449,716,000 1,306,993,000
Balance, beginning of period 0 0
Gross Unrealized Gains 3,103,000 3,184,000
Gross Unrealized Losses (5,401,000) (6,295,000)
Fair Value 1,447,418,000 1,303,882,000
Private label MBS [Member]    
Debt Securities, Available-for-sale [Line Items]    
AFS Securities - Amortized Cost, [1] 112,175,000 115,432,000
Balance, beginning of period 18,959,000 16,713,000
Gross Unrealized Gains 3,724,000 4,626,000
Gross Unrealized Losses (1,335,000) (1,217,000)
Fair Value 95,605,000 102,128,000
MBS [Member]    
Debt Securities, Available-for-sale [Line Items]    
AFS Securities - Amortized Cost, [1] 14,528,597,000 12,269,296,000
Balance, beginning of period 18,959,000 16,713,000
Gross Unrealized Gains 68,774,000 54,942,000
Gross Unrealized Losses (39,429,000) (39,374,000)
Fair Value 14,538,983,000 12,268,151,000
U.S. Treasury obligations    
Debt Securities, Available-for-sale [Line Items]    
AFS Securities - Amortized Cost, 5,100,392,000 4,902,802,000
Balance, beginning of period 0 0
Gross Unrealized Gains 6,424,000 9,749,000
Gross Unrealized Losses (1,338,000) (271,000)
Fair Value 5,105,478,000 4,912,280,000
Single Family [Member] | GSE MBS [Member]    
Debt Securities, Available-for-sale [Line Items]    
AFS Securities - Amortized Cost, [1] 5,868,338,000 4,568,337,000
Balance, beginning of period 0 0
Gross Unrealized Gains 11,410,000 6,899,000
Gross Unrealized Losses (27,194,000) (27,463,000)
Fair Value 5,852,554,000 4,547,773,000
Multifamily [Member] | GSE MBS [Member]    
Debt Securities, Available-for-sale [Line Items]    
AFS Securities - Amortized Cost, [1] 7,098,368,000 6,278,534,000
Balance, beginning of period 0 0
Gross Unrealized Gains 50,537,000 40,233,000
Gross Unrealized Losses (5,499,000) (4,399,000)
Fair Value $ 7,143,406,000 $ 6,314,368,000
[1] Includes adjustments made to the cost basis of investments for accretion, amortization and/or fair value hedge accounting adjustments, and excludes accrued interest receivable of $66.4 million at June 30, 2026 and $59.1 million at December 31, 2025.