Commitments and Contingencies - Other Commitments (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2026	Dec. 31, 2025
Loss Contingencies [Line Items]
Payment for half of subscribed shares	$ 5,400	$ 5,400
Resale And Forward-Dated Resale And Securities Borrowing Agreements And Forward-Dated Repurchase And Securities Lending Agreements
Loss Contingencies [Line Items]
Other commitment, expiration term (in months)	12 months
Resale and Forward-Dated Resale and Securities Borrowing Agreements
Loss Contingencies [Line Items]
Other commitments	$ 220,300	149,000
Forward-Dated Repurchase and Securities Lending Agreements
Loss Contingencies [Line Items]
Other commitments	151,900	108,900
Auto Loans and Leases
Loss Contingencies [Line Items]
Other commitment, due in next twelve months	$ 3,800	4,000
Other commitment, termination prior notice period	12 months
Debt and Equity Security Commitments
Loss Contingencies [Line Items]
Other commitments	$ 1,800	884
Residential and Commercial Portfolio Segments \| Loan Purchase Commitments \| Residential and Commercial Financing Receivable
Loss Contingencies [Line Items]
Other commitments	859	700
Commercial \| Loan Purchase Commitments
Loss Contingencies [Line Items]
Other commitments	$ 538	$ 558