Fair Value Measurements - EGTS - Debt (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	$ 52,720	$ 51,635
Carrying Value | EGTS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	1,583	1,582
Level 2 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	45,166	46,906
Level 2 | Fair Value | EGTS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	$ 1,275	$ 1,337