v3.26.1
Debt Securities Available for Sale - AFS debt securities in a continuous unrealized loss position (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Schedule of Available-for-sale Securities [Line Items]    
Less than 12 months Fair Value $ 11,833,268 $ 1,215,897
Less than 12 months Gross Unrealized Losses 26,834 10,060
12 months or more Fair Value 4,852,864 5,496,062
12 months or more Gross Unrealized Losses 890,677 892,407
Total Fair Value 16,686,132 6,711,959
Total Gross Unrealized Losses 917,511 902,467
US Treasury Securities    
Schedule of Available-for-sale Securities [Line Items]    
Less than 12 months Fair Value 11,616,601 992,083
Less than 12 months Gross Unrealized Losses 17,111 82
12 months or more Fair Value 442,317 943,699
12 months or more Gross Unrealized Losses 20,254 20,752
Total Fair Value 12,058,918 1,935,782
Total Gross Unrealized Losses 37,365 20,834
Collateralized Mortgage Obligations - Federal agencies    
Schedule of Available-for-sale Securities [Line Items]    
Less than 12 months Fair Value 4,568 1,481
Less than 12 months Gross Unrealized Losses 45 3
12 months or more Fair Value 75,409 83,266
12 months or more Gross Unrealized Losses 6,716 6,509
Total Fair Value 79,977 84,747
Total Gross Unrealized Losses 6,761 6,512
Mortgage Backed Securities    
Schedule of Available-for-sale Securities [Line Items]    
Less than 12 months Fair Value 212,099 222,333
Less than 12 months Gross Unrealized Losses 9,678 9,975
12 months or more Fair Value 4,335,138 4,469,097
12 months or more Gross Unrealized Losses 863,707 865,146
Total Fair Value 4,547,237 4,691,430
Total Gross Unrealized Losses $ 873,385 $ 875,121