v3.26.1
AFS Debt Securities, Contractual Maturities (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]    
Available-for-sale, at amortized cost, net of allowance for credit losses, excluding portfolio level basis adjustments $ 226,400 $ 215,700
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year 2,832  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years 10,142  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years 56,784  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years 156,642  
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]    
Available-for-sale, at fair value 222,873 213,573
Available-for-sale, fair value, remaining contractual maturity, due within one year 2,832  
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years 9,887  
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years 56,817  
Available-for-sale, fair value, remaining contractual maturity, due after ten years $ 153,337  
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]    
Available-for-sale, weighted average yield 4.30%  
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year 3.40%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years 2.38%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years 4.13%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years 4.51%  
AFS and HTM Debt Securities Textual [Abstract]    
Debt securities, available-for-sale, maturity allocation [Extensible Enumeration] Debt Securities, Maturity Allocation, Contractual Maturity [Member]  
Fair value hedging [Member]    
AFS and HTM Debt Securities Textual [Abstract]    
Portfolio level basis adjustments $ (41) 75
Securities of U.S. Treasury and federal agencies [Member]    
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]    
Available-for-sale, at amortized cost, net of allowance for credit losses, excluding portfolio level basis adjustments 57,824 51,738
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year 1,978  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years 5,655  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years 49,395  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years 796  
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]    
Available-for-sale, at fair value 57,687  
Available-for-sale, fair value, remaining contractual maturity, due within one year 1,978  
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years 5,495  
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years 49,471  
Available-for-sale, fair value, remaining contractual maturity, due after ten years $ 743  
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]    
Available-for-sale, weighted average yield 3.89%  
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year 3.58%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years 1.79%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years 4.13%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years 4.53%  
Securities of U.S. states and political subdivisions [Member]    
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]    
Available-for-sale, at amortized cost, net of allowance for credit losses, excluding portfolio level basis adjustments $ 10,278 10,706
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year 819  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years 3,754  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years 2,154  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years 3,551  
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]    
Available-for-sale, at fair value 9,943 10,397
Available-for-sale, fair value, remaining contractual maturity, due within one year 815  
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years 3,653  
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years 2,078  
Available-for-sale, fair value, remaining contractual maturity, due after ten years $ 3,397  
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]    
Available-for-sale, weighted average yield 3.23%  
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year 2.86%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years 2.83%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years 3.37%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years 3.64%  
Federal agency mortgage-backed securities [Member]    
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]    
Available-for-sale, at amortized cost, net of allowance for credit losses, excluding portfolio level basis adjustments $ 147,913 142,022
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year 1  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years 527  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years 4,809  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years 142,576  
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]    
Available-for-sale, at fair value 144,822  
Available-for-sale, fair value, remaining contractual maturity, due within one year 1  
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years 525  
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years 4,808  
Available-for-sale, fair value, remaining contractual maturity, due after ten years $ 139,488  
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]    
Available-for-sale, weighted average yield 4.50%  
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year 1.93%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years 3.99%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years 4.42%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years 4.50%  
Non-agency mortgage-backed securities [Member]    
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]    
Available-for-sale, at amortized cost, net of allowance for credit losses, excluding portfolio level basis adjustments $ 1,868 2,141
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year 0  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years 0  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years 8  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years 1,860  
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]    
Available-for-sale, at fair value 1,858  
Available-for-sale, fair value, remaining contractual maturity, due within one year 0  
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years 0  
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years 8  
Available-for-sale, fair value, remaining contractual maturity, due after ten years $ 1,850  
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]    
Available-for-sale, weighted average yield 4.45%  
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year 0.00%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years 0.00%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years 4.30%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years 4.45%  
Collateralized loan obligations [Member]    
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]    
Available-for-sale, at amortized cost, net of allowance for credit losses, excluding portfolio level basis adjustments $ 8,210 7,895
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year 0  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years 0  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years 374  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years 7,836  
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]    
Available-for-sale, at fair value 8,205 7,904
Available-for-sale, fair value, remaining contractual maturity, due within one year 0  
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years 0  
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years 374  
Available-for-sale, fair value, remaining contractual maturity, due after ten years $ 7,831  
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]    
Available-for-sale, weighted average yield 5.01%  
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year 0.00%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years 0.00%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years 5.11%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years 5.00%  
Other debt securities [Member]    
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]    
Available-for-sale, at amortized cost, net of allowance for credit losses, excluding portfolio level basis adjustments $ 307 $ 1,198
Available-for-sale, amortized cost, net, remaining contractual maturity, due within one year 34  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after one year through five years 206  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after five years through ten years 44  
Available-for-sale, amortized cost, net, remaining contractual maturity, due after ten years 23  
Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling Maturity, Fair Value [Abstract]    
Available-for-sale, at fair value 358  
Available-for-sale, fair value, remaining contractual maturity, due within one year 38  
Available-for-sale, fair value, remaining contractual maturity, due after one year through five years 214  
Available-for-sale, fair value, remaining contractual maturity, due after five years through ten years 78  
Available-for-sale, fair value, remaining contractual maturity, due after ten years $ 28  
Debt Securities, Available-for-Sale, Rolling Maturity, Weighted Average Yield [Abstract]    
Available-for-sale, weighted average yield 5.47%  
Available-for-sale, weighted average yield, remaining contractual maturity, due within one year 6.16%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after one year through five years 6.38%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after five years through ten years 3.24%  
Available-for-sale, weighted average yield, remaining contractual maturity, due after ten years 0.57%