HTM Debt Securities, Contractual Maturities (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Rolling Maturity [Abstract]
Held-to-maturity, amortized cost, net	$ 198,573	$ 208,023
Held-to-maturity, amortized cost, net, remaining contractual maturity, due within one year	96
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after one year through five years	2,296
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after five years through ten years	2,738
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after ten years	193,443
Debt Securities, Held-to-Maturity, Maturity, Allocated and Single Maturity Date, Fair Value, Rolling Maturity [Abstract]
Held-to-maturity, fair value	166,165	175,797
Held-to-maturity, fair value, remaining contractual maturity, due within one year	97
Held-to-maturity, fair value, remaining contractual maturity, due after one year through five years	2,283
Held-to-maturity, fair value, remaining contractual maturity, due after five years through ten years	2,736
Held-to-maturity, fair value, remaining contractual maturity, due after ten years	$ 161,049
Debt Securities, Held-to-Maturity, Rolling Maturity, Weighted Average Yield [Abstract]
Held-to-maturity weighted average yield	2.42%
Held-to-maturity, weighted average yield, remaining contractual maturity, due within one year	1.39%
Held-to-maturity, weighted average yield, remaining contractual maturity, due after one year through five years	4.72%
Held-to-maturity, weighted average yield, remaining contractual maturity, due after five years through ten years	4.91%
Held-to-maturity, weighed average yield, remaining contractual maturity, due after ten years	2.36%
AFS and HTM Debt Securities Textual [Abstract]
Debt securities, held-to-maturity, amortized cost, after allowance for credit loss, maturity allocation basis [Extensible Enumeration]	Debt Securities, Maturity Allocation, Contractual Maturity [Member]
Securities of U.S. Treasury and federal agencies [Member]
Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Rolling Maturity [Abstract]
Held-to-maturity, amortized cost, net	$ 3,800	3,797
Held-to-maturity, amortized cost, net, remaining contractual maturity, due within one year	0
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after one year through five years	0
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after five years through ten years	0
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after ten years	3,800
Debt Securities, Held-to-Maturity, Maturity, Allocated and Single Maturity Date, Fair Value, Rolling Maturity [Abstract]
Held-to-maturity, fair value	2,043	2,050
Held-to-maturity, fair value, remaining contractual maturity, due within one year	0
Held-to-maturity, fair value, remaining contractual maturity, due after one year through five years	0
Held-to-maturity, fair value, remaining contractual maturity, due after five years through ten years	0
Held-to-maturity, fair value, remaining contractual maturity, due after ten years	$ 2,043
Debt Securities, Held-to-Maturity, Rolling Maturity, Weighted Average Yield [Abstract]
Held-to-maturity weighted average yield	1.60%
Held-to-maturity, weighted average yield, remaining contractual maturity, due within one year	0.00%
Held-to-maturity, weighted average yield, remaining contractual maturity, due after one year through five years	0.00%
Held-to-maturity, weighted average yield, remaining contractual maturity, due after five years through ten years	0.00%
Held-to-maturity, weighed average yield, remaining contractual maturity, due after ten years	1.60%
Securities of U.S. states and political subdivisions [Member]
Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Rolling Maturity [Abstract]
Held-to-maturity, amortized cost, net	$ 17,249	17,476
Held-to-maturity, amortized cost, net, remaining contractual maturity, due within one year	87
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after one year through five years	460
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after five years through ten years	404
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after ten years	16,298
Debt Securities, Held-to-Maturity, Maturity, Allocated and Single Maturity Date, Fair Value, Rolling Maturity [Abstract]
Held-to-maturity, fair value	14,313	14,208
Held-to-maturity, fair value, remaining contractual maturity, due within one year	86
Held-to-maturity, fair value, remaining contractual maturity, due after one year through five years	454
Held-to-maturity, fair value, remaining contractual maturity, due after five years through ten years	392
Held-to-maturity, fair value, remaining contractual maturity, due after ten years	$ 13,381
Debt Securities, Held-to-Maturity, Rolling Maturity, Weighted Average Yield [Abstract]
Held-to-maturity weighted average yield	2.52%
Held-to-maturity, weighted average yield, remaining contractual maturity, due within one year	1.27%
Held-to-maturity, weighted average yield, remaining contractual maturity, due after one year through five years	2.30%
Held-to-maturity, weighted average yield, remaining contractual maturity, due after five years through ten years	2.74%
Held-to-maturity, weighed average yield, remaining contractual maturity, due after ten years	2.53%
Federal agency mortgage-backed securities [Member]
Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Rolling Maturity [Abstract]
Held-to-maturity, amortized cost, net	$ 171,852	178,882
Held-to-maturity, amortized cost, net, remaining contractual maturity, due within one year	0
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after one year through five years	0
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after five years through ten years	0
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after ten years	171,852
Debt Securities, Held-to-Maturity, Maturity, Allocated and Single Maturity Date, Fair Value, Rolling Maturity [Abstract]
Held-to-maturity, fair value	144,109	151,608
Held-to-maturity, fair value, remaining contractual maturity, due within one year	0
Held-to-maturity, fair value, remaining contractual maturity, due after one year through five years	0
Held-to-maturity, fair value, remaining contractual maturity, due after five years through ten years	0
Held-to-maturity, fair value, remaining contractual maturity, due after ten years	$ 144,109
Debt Securities, Held-to-Maturity, Rolling Maturity, Weighted Average Yield [Abstract]
Held-to-maturity weighted average yield	2.34%
Held-to-maturity, weighted average yield, remaining contractual maturity, due within one year	0.00%
Held-to-maturity, weighted average yield, remaining contractual maturity, due after one year through five years	0.00%
Held-to-maturity, weighted average yield, remaining contractual maturity, due after five years through ten years	0.00%
Held-to-maturity, weighed average yield, remaining contractual maturity, due after ten years	2.34%
Non-agency mortgage-backed securities [Member]
Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Rolling Maturity [Abstract]
Held-to-maturity, amortized cost, net	$ 1,540	1,497
Held-to-maturity, amortized cost, net, remaining contractual maturity, due within one year	9
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after one year through five years	11
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after five years through ten years	27
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after ten years	1,493
Debt Securities, Held-to-Maturity, Maturity, Allocated and Single Maturity Date, Fair Value, Rolling Maturity [Abstract]
Held-to-maturity, fair value	1,576	1,540
Held-to-maturity, fair value, remaining contractual maturity, due within one year	11
Held-to-maturity, fair value, remaining contractual maturity, due after one year through five years	17
Held-to-maturity, fair value, remaining contractual maturity, due after five years through ten years	32
Held-to-maturity, fair value, remaining contractual maturity, due after ten years	$ 1,516
Debt Securities, Held-to-Maturity, Rolling Maturity, Weighted Average Yield [Abstract]
Held-to-maturity weighted average yield	3.88%
Held-to-maturity, weighted average yield, remaining contractual maturity, due within one year	2.47%
Held-to-maturity, weighted average yield, remaining contractual maturity, due after one year through five years	6.24%
Held-to-maturity, weighted average yield, remaining contractual maturity, due after five years through ten years	3.07%
Held-to-maturity, weighed average yield, remaining contractual maturity, due after ten years	3.88%
Collateralized loan obligations [Member]
Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Rolling Maturity [Abstract]
Held-to-maturity, amortized cost, net	$ 2,414	4,655
Held-to-maturity, amortized cost, net, remaining contractual maturity, due within one year	0
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after one year through five years	107
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after five years through ten years	2,307
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after ten years	0
Debt Securities, Held-to-Maturity, Maturity, Allocated and Single Maturity Date, Fair Value, Rolling Maturity [Abstract]
Held-to-maturity, fair value	2,420	4,674
Held-to-maturity, fair value, remaining contractual maturity, due within one year	0
Held-to-maturity, fair value, remaining contractual maturity, due after one year through five years	108
Held-to-maturity, fair value, remaining contractual maturity, due after five years through ten years	2,312
Held-to-maturity, fair value, remaining contractual maturity, due after ten years	$ 0
Debt Securities, Held-to-Maturity, Rolling Maturity, Weighted Average Yield [Abstract]
Held-to-maturity weighted average yield	5.35%
Held-to-maturity, weighted average yield, remaining contractual maturity, due within one year	0.00%
Held-to-maturity, weighted average yield, remaining contractual maturity, due after one year through five years	5.96%
Held-to-maturity, weighted average yield, remaining contractual maturity, due after five years through ten years	5.32%
Held-to-maturity, weighed average yield, remaining contractual maturity, due after ten years	0.00%
Other debt securities [Member]
Debt Securities, Held-to-Maturity, Amortized Cost Excluding Accrued Interest, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Rolling Maturity [Abstract]
Held-to-maturity, amortized cost, net	$ 1,718	1,716
Held-to-maturity, amortized cost, net, remaining contractual maturity, due within one year	0
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after one year through five years	1,718
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after five years through ten years	0
Held-to-maturity, amortized cost, net, remaining contractual maturity, due after ten years	0
Debt Securities, Held-to-Maturity, Maturity, Allocated and Single Maturity Date, Fair Value, Rolling Maturity [Abstract]
Held-to-maturity, fair value	1,704	$ 1,717
Held-to-maturity, fair value, remaining contractual maturity, due within one year	0
Held-to-maturity, fair value, remaining contractual maturity, due after one year through five years	1,704
Held-to-maturity, fair value, remaining contractual maturity, due after five years through ten years	0
Held-to-maturity, fair value, remaining contractual maturity, due after ten years	$ 0
Debt Securities, Held-to-Maturity, Rolling Maturity, Weighted Average Yield [Abstract]
Held-to-maturity weighted average yield	5.27%
Held-to-maturity, weighted average yield, remaining contractual maturity, due within one year	0.00%
Held-to-maturity, weighted average yield, remaining contractual maturity, due after one year through five years	5.27%
Held-to-maturity, weighted average yield, remaining contractual maturity, due after five years through ten years	0.00%
Held-to-maturity, weighed average yield, remaining contractual maturity, due after ten years	0.00%

Amount excluding accrued interest, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date, maturing after rolling tenth fiscal year following current statement of financial position date. For interim and annual periods when interim period is reported on rolling approach.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-5

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 320
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477268/942-320-50-3