v3.26.1
Held-to-maturity Securities (Held-to-maturity by Major Security Type) (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Schedule of Held-to-maturity Securities [Line Items]    
Held-to-Maturity, Amortized Cost [1] $ 22,307 $ 24,658
Held-to-maturity securities Gross Unrealized Gains 58 68
Gross Unrealized Losses on held-to-maturity securities (205) (217)
Held-to-maturity securities, fair value 22,160 24,509
Held-to-Maturity, Accrued Interest Receivable   43
State or local housing agency debt obligations [Member]    
Schedule of Held-to-maturity Securities [Line Items]    
Held-to-Maturity, Amortized Cost [1] 6 1
Held-to-maturity securities Gross Unrealized Gains 0 0
Gross Unrealized Losses on held-to-maturity securities 0 0
Held-to-maturity securities, fair value 6 1
Government-Sponsored Enterprises Debt Obligations [Member]    
Schedule of Held-to-maturity Securities [Line Items]    
Held-to-Maturity, Amortized Cost [1] 360 360
Held-to-maturity securities Gross Unrealized Gains 2 2
Gross Unrealized Losses on held-to-maturity securities 0 0
Held-to-maturity securities, fair value 362 362
Residential [Member] | U.S. agency obligations-guaranteed residential [Member]    
Schedule of Held-to-maturity Securities [Line Items]    
Held-to-Maturity, Amortized Cost [1] 1,656 1,876
Held-to-maturity securities Gross Unrealized Gains 4 12
Gross Unrealized Losses on held-to-maturity securities (20) (21)
Held-to-maturity securities, fair value 1,640 1,867
Residential [Member] | Government-sponsored enterprises [Member]    
Schedule of Held-to-maturity Securities [Line Items]    
Held-to-Maturity, Amortized Cost [1] 9,710 10,559
Held-to-maturity securities Gross Unrealized Gains 45 43
Gross Unrealized Losses on held-to-maturity securities (82) (90)
Held-to-maturity securities, fair value 9,673 10,512
Commercial [Member] | Government-sponsored enterprises [Member]    
Schedule of Held-to-maturity Securities [Line Items]    
Held-to-Maturity, Amortized Cost [1] 10,575 11,862
Held-to-maturity securities Gross Unrealized Gains 7 11
Gross Unrealized Losses on held-to-maturity securities (103) (106)
Held-to-maturity securities, fair value $ 10,479 $ 11,767
[1] Excludes accrued interest receivable of $36 and $43 as of June 30, 2026 and December 31, 2025, respectively