Derivative Financial Instruments - Carrying Amount and Cumulative Basis Adjustments for Hedge Accounting (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Derivatives designated as hedging instruments | Long-term debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Carrying Amount of Assets	$ 12,513	$ 9,026
Active	(644)	(64)
Derivatives designated as hedging instruments | Total available-for-sale investment securities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Carrying Amount of Assets	9,801	3,551
Active	(675)	0
Derivatives designated as hedging instruments | Total available-for-sale investment securities | Closed Portfolio
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Carrying Amount of Assets	207
Active	(4)
Last-of-layer, amount	64
Derivatives not designated as hedging instruments | Long-term debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Carrying Amount of Assets	362	514
Derivatives not designated as hedging instruments | Total available-for-sale investment securities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Carrying Amount of Assets	$ 8	$ 24