Fair Value - Schedule of Fair Value Measurement Inputs and Valuation Techniques (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Corporate bonds	$ 16,661	$ 8,995
Interest rate & other derivative — non-qualifying hedges	904	159
Fair value of derivative financial instruments	912	486
Fair Value, Recurring
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Corporate bonds	16,661	8,995
Interest rate & other derivative — non-qualifying hedges	904	159
Fair value of derivative financial instruments	912	486
Fair Value, Recurring | Corporate Bonds
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Corporate bonds	478	536
Fair Value, Recurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Corporate bonds	152	174
Interest rate & other derivative — non-qualifying hedges	6	0
Fair value of derivative financial instruments	1	0
Fair Value, Recurring | Level 3 | Corporate Bonds
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Corporate bonds	152	$ 174
Fair Value, Recurring | Level 3 | Interest Rate and Other Derivative
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Interest rate & other derivative — non-qualifying hedges	5
Fair value of derivative financial instruments	$ 1