Derivative Financial Instruments - Carrying Amount and Cumulative Basis Adjustments for Hedge Accounting (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Prepayable financial asset closed portfolio, amortized cost	$ 713	$ 207
Prepayable financial asset closed portfolio, last-of-layer, amortized cost	400	64
Cumulative adjustment associated with hedging relationships	(13)	(4)
Hedged Items Currently Designated | Long-term debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Carrying Amount of Hedged Assets/Liabilities	12,762	12,513
Cumulative Hedge Accounting Basis Adjustments	(518)	(644)
Hedged Items Currently Designated | Available-For-Sale Debt Securities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Carrying Amount of Hedged Assets/Liabilities	10,326	9,801
Cumulative Hedge Accounting Basis Adjustments	(719)	(675)
De-designated | Long-term debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative Hedge Accounting Basis Adjustments	200	362
De-designated | Available-For-Sale Debt Securities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative Hedge Accounting Basis Adjustments	$ 5	$ 8