Property and Equipment, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 76,634	$ 73,189
Less accumulated depreciation and amortization	(12,101)	(10,004)
Property and Equipment, Net	64,533	63,185
Finance lease, property and equipment, net	445
Finance lease, accumulated amortization	349
Capital eased asset, Net		479
capital lease, amortization		(282)
Right-to-use fixed assets	1,100	1,100
Amortization of leased asset, capital lease	338	310
Interest costs capitalized	15	24	$ 22
Land for transportation purposes
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	6,280	6,218
Track structure
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	25,599	24,214
Other roadway
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	30,525	29,077
Locomotives
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	8,533	8,660
Freight cars and other equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,567	3,100
Computer hardware, software and other
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	1,382	1,256
Construction in progress
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 748	$ 664
Minimum | Track structure
Property, Plant and Equipment [Line Items]
Useful life	15 years
Minimum | Other roadway
Property, Plant and Equipment [Line Items]
Useful life	10 years
Minimum | Locomotives
Property, Plant and Equipment [Line Items]
Useful life	8 years
Minimum | Freight cars and other equipment
Property, Plant and Equipment [Line Items]
Useful life	8 years
Minimum | Computer hardware, software and other
Property, Plant and Equipment [Line Items]
Useful life	6 years
Maximum | Track structure
Property, Plant and Equipment [Line Items]
Useful life	50 years
Maximum | Other roadway
Property, Plant and Equipment [Line Items]
Useful life	100 years
Maximum | Locomotives
Property, Plant and Equipment [Line Items]
Useful life	36 years
Maximum | Freight cars and other equipment
Property, Plant and Equipment [Line Items]
Useful life	41 years
Maximum | Computer hardware, software and other
Property, Plant and Equipment [Line Items]
Useful life	15 years