Investments - Schedule of Investments (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Schedule of Investments [Line Items]
Long-term investments:	$ 3,316	$ 3,184
COLI at net cash surrender value	751	161
Other investments	22	25
Total long-term investments	4,089	3,370
Conrail
Schedule of Investments [Line Items]
Long-term investments:	1,827	1,748
TTX
Schedule of Investments [Line Items]
Long-term investments:	1,056	1,013
Other
Schedule of Investments [Line Items]
Long-term investments:	$ 433	$ 423