Derivative Instruments and Other Financial Instruments Used For Hedging - Derivative Instruments Fair Value Hedging Relationships for the Carrying Amount of the Hedging Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Liability, Fair Value Hedge	$ 2,049	$ 2,050
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	(1)	0
Long-term Debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged Liability, Fair Value Hedge	2,049	2,050
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	$ (1)	$ 0