Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Disaggregation of Revenue [Line Items]
Retained Earnings (Accumulated Deficit)				$ 3
Accounts Receivable, Net	$ 1,300			1,200
Revenue from Contract with Customer, Excluding Assessed Tax	23,855	$ 21,387	$ 19,829
Total Freight Revenues	22,578	20,406	18,921
Total other revenues	1,277	981	908
Revenue, Remaining Performance Obligation, Amount	237			$ 192
Industrial Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	5,967	5,133	4,764
Agricultural Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,697	4,316	4,240
Coal [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,012	3,846	3,383
non-rail logistics subsidiary [Domain]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	856	640	551
Accessorial and other [Domain]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	421	341	357
Consumer Products [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 7,902	$ 7,111	$ 6,534