v3.26.1
Note 4 - Investment Securities - Investment Securities With Unrealized Losses (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Less than 12 months fair value $ 26,220 $ 182,187
Less than 12 months unrealized losses 151 3,093
12 months or more fair value 150,589 200,701
12 months or more unrealized losses 19,736 33,135
Total fair value 176,809 382,888
Total unrealized losses 19,887 36,228
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises [Member]    
Less than 12 months fair value 16,496 107,328
Less than 12 months unrealized losses 109 1,917
12 months or more fair value 63,328 94,506
12 months or more unrealized losses 6,955 13,539
Total fair value 79,824 201,834
Total unrealized losses 7,064 15,456
Commercial Mortgage Backed Securities Issued by US Government Agencies [Member]    
Less than 12 months fair value 6,941 55,921
Less than 12 months unrealized losses 35 926
12 months or more fair value 51,781 57,735
12 months or more unrealized losses 8,307 11,030
Total fair value 58,722 113,656
Total unrealized losses 8,342 11,956
US States and Political Subdivisions Debt Securities [Member]    
Less than 12 months fair value 2,783 18,938
Less than 12 months unrealized losses 7 250
12 months or more fair value 35,480 48,460
12 months or more unrealized losses 4,474 8,566
Total fair value 38,263 67,398
Total unrealized losses $ 4,481 $ 8,816