v3.25.3
Goodwill and Intangible Assets - Intangible assets subject to amortization, net (Details) - USD ($)
$ in Millions
Sep. 30, 2025
Dec. 31, 2024
Dec. 31, 2023
Goodwill and Intangible Assets      
Gross carrying amount $ 692 $ 680 $ 671
Accumulated amortization (312) (269) (210)
Net carrying amount 380 411 461
Customer relationships      
Goodwill and Intangible Assets      
Gross carrying amount 515 515 515
Accumulated amortization (204) (173) (132)
Net carrying amount 311 342 383
Other amortizable intangible assets      
Goodwill and Intangible Assets      
Gross carrying amount 177 165 156
Accumulated amortization (108) (96) (78)
Net carrying amount $ 69 $ 69 $ 78