v3.26.1
Investment Securities - Amortized Cost, Fair Value and Yield by Maturity Date (Details) - USD ($)
$ in Millions
 6 Months Ended 9 Months Ended
Jun. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Amortized Cost      
Amortized Cost $ 74,085   $ 76,170
Fair Value      
Fair Value $ 64,622   $ 67,079
Weighted- Average Maturity in Years      
Total 8 years 1 month 6 days    
Weighted-Average Yield      
Total 2.35%   2.34%
Weighted average maturity of total held to maturity investment securities   7 years 10 months 24 days  
Amortized Cost      
Amortized Cost $ 93,526    
Fair Value      
Fair Value [1] $ 89,085   $ 90,838
Weighted- Average Maturity in Years      
Total 5 years 9 months 18 days 5 years 6 months  
Weighted-Average Yield      
Total 3.73%   3.55%
Federal statutory rate 21.00%    
Portfolio basis adjustments excluded from amortized cost $ 3    
U.S. Treasury and agencies      
Amortized Cost      
Maturing in one year or less 649    
Maturing after one year through five years 0    
Maturing after five years through ten years 0    
Maturing after ten years 0    
Amortized Cost 649   $ 648
Fair Value      
Maturing in one year or less 643    
Maturing after one year through five years 0    
Maturing after five years through ten years 0    
Maturing after ten years 0    
Fair Value $ 643   644
Weighted- Average Maturity in Years      
Maturing in one year or less 9 months 18 days    
Total 9 months 18 days    
Weighted-Average Yield      
Maturing in one year or less 3.00%    
Maturing after one year through five years 0.00%    
Maturing after five years through ten years 0.00%    
Maturing after ten years 0.00%    
Total 3.00%    
Maturing in one year or less 1 month 6 days    
Amortized Cost      
Maturing in one year or less $ 10    
Maturing after one year through five years 21,585    
Maturing after five years through ten years 8,525    
Maturing after ten years 0    
Amortized Cost 30,120    
Fair Value      
Maturing in one year or less 10    
Maturing after one year through five years 21,062    
Maturing after five years through ten years 7,683    
Maturing after ten years 0    
Fair Value $ 28,755   28,770
Weighted- Average Maturity in Years      
Maturing in one year or less 1 month 6 days    
Maturing after one year through five years 3 years 1 month 6 days    
Maturing after five years through ten years 6 years 2 months 12 days    
Total 4 years    
Weighted-Average Yield      
Maturing in one year or less 3.68%    
Maturing after one year through five years 3.27%    
Maturing after five years through ten years 2.69%    
Maturing after ten years 0.00%    
Total 3.11%    
Mortgage-backed securities      
Amortized Cost      
Maturing in one year or less $ 144    
Maturing after one year through five years 1,705    
Maturing after five years through ten years 71,300    
Maturing after ten years 6    
Amortized Cost 73,155    
Fair Value      
Maturing in one year or less 145    
Maturing after one year through five years 1,704    
Maturing after five years through ten years 61,841    
Maturing after ten years 6    
Fair Value $ 63,696    
Weighted- Average Maturity in Years      
Maturing in one year or less 7 months 6 days    
Maturing after one year through five years 3 years    
Maturing after five years through ten years 8 years 3 months 18 days    
Maturing after ten years 17 years 8 months 12 days    
Total 8 years 1 month 6 days    
Weighted-Average Yield      
Maturing in one year or less 4.95%    
Maturing after one year through five years 4.43%    
Maturing after five years through ten years 2.29%    
Maturing after ten years 5.91%    
Total 2.35%    
Maturing in one year or less 2 months 12 days    
Amortized Cost      
Maturing in one year or less $ 86    
Maturing after one year through five years 10,354    
Maturing after five years through ten years 39,050    
Maturing after ten years 83    
Amortized Cost 49,573    
Fair Value      
Maturing in one year or less 86    
Maturing after one year through five years 9,420    
Maturing after five years through ten years 37,710    
Maturing after ten years 80    
Fair Value $ 47,296    
Weighted- Average Maturity in Years      
Maturing in one year or less 2 months 12 days    
Maturing after one year through five years 4 years    
Maturing after five years through ten years 6 years 10 months 24 days    
Maturing after ten years 11 years 2 months 12 days    
Total 6 years 3 months 18 days    
Weighted-Average Yield      
Maturing in one year or less 2.13%    
Maturing after one year through five years 1.95%    
Maturing after five years through ten years 4.54%    
Maturing after ten years 4.70%    
Total 4.00%    
Asset-backed securities      
Weighted-Average Yield      
Maturing in one year or less 1 year    
Amortized Cost      
Maturing in one year or less $ 1,120    
Maturing after one year through five years 2,300    
Maturing after five years through ten years 2,110    
Maturing after ten years 0    
Amortized Cost 5,530    
Fair Value      
Maturing in one year or less 1,124    
Maturing after one year through five years 2,301    
Maturing after five years through ten years 2,110    
Maturing after ten years 0    
Fair Value $ 5,535   6,527
Weighted- Average Maturity in Years      
Maturing in one year or less 1 year    
Maturing after one year through five years 4 years 7 months 6 days    
Maturing after five years through ten years 5 years 6 months    
Total 4 years 2 months 12 days    
Weighted-Average Yield      
Maturing in one year or less 4.55%    
Maturing after one year through five years 4.99%    
Maturing after five years through ten years 4.89%    
Maturing after ten years 0.00%    
Total 4.86%    
Obligations of state and political subdivisions      
Weighted-Average Yield      
Maturing in one year or less 6 months    
Amortized Cost      
Maturing in one year or less $ 794    
Maturing after one year through five years 783    
Maturing after five years through ten years 1,396    
Maturing after ten years 5,193    
Amortized Cost 8,166    
Fair Value      
Maturing in one year or less 793    
Maturing after one year through five years 776    
Maturing after five years through ten years 1,307    
Maturing after ten years 4,485    
Fair Value $ 7,361   9,514
Weighted- Average Maturity in Years      
Maturing in one year or less 6 months    
Maturing after one year through five years 2 years 8 months 12 days    
Maturing after five years through ten years 7 years 7 months 6 days    
Maturing after ten years 13 years 7 months 6 days    
Total 10 years 3 months 18 days    
Weighted-Average Yield      
Maturing in one year or less 4.69%    
Maturing after one year through five years 4.16%    
Maturing after five years through ten years 3.47%    
Maturing after ten years 3.41%    
Total 3.62%    
Other      
Amortized Cost      
Maturing in one year or less $ 145    
Maturing after one year through five years 136    
Maturing after five years through ten years 0    
Maturing after ten years 0    
Amortized Cost 281   287
Fair Value      
Maturing in one year or less 145    
Maturing after one year through five years 138    
Maturing after five years through ten years 0    
Maturing after ten years 0    
Fair Value $ 283   289
Weighted- Average Maturity in Years      
Maturing in one year or less 4 months 24 days    
Maturing after one year through five years 1 year 8 months 12 days    
Total 1 year    
Weighted-Average Yield      
Maturing in one year or less 2.62%    
Maturing after one year through five years 2.68%    
Maturing after five years through ten years 0.00%    
Maturing after ten years 0.00%    
Total 2.65%    
Maturing in one year or less 4 months 24 days    
Amortized Cost      
Maturing in one year or less $ 72    
Maturing after one year through five years 65    
Maturing after five years through ten years 0    
Maturing after ten years 0    
Amortized Cost 137    
Fair Value      
Maturing in one year or less 72    
Maturing after one year through five years 66    
Maturing after five years through ten years 0    
Maturing after ten years 0    
Fair Value $ 138   $ 268
Weighted- Average Maturity in Years      
Maturing in one year or less 4 months 24 days    
Maturing after one year through five years 2 years 9 months 18 days    
Total 1 year 7 months 6 days    
Weighted-Average Yield      
Maturing in one year or less 4.62%    
Maturing after one year through five years 4.53%    
Maturing after five years through ten years 0.00%    
Maturing after ten years 0.00%    
Total 4.58%    
[1] Includes only collateral pledged by the Company where counterparties have the right to sell or pledge the collateral.