Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of revenue
Revenue from contracts with customers	$ 896	$ 938	$ 2,722	$ 2,831
Operating lease income	26	25	77	75
Total operating revenues	922	963	2,799	2,906
Transferred over time
Disaggregation of revenue
Revenue from contracts with customers	721	737	2,168	2,214
Transferred over time | Retail service
Disaggregation of revenue
Revenue from contracts with customers	669	687	2,014	2,065
Transferred over time | Other service
Disaggregation of revenue
Revenue from contracts with customers	52	50	154	149
Transferred at point in time | Equipment sales
Disaggregation of revenue
Revenue from contracts with customers	$ 175	$ 201	$ 554	$ 617