Property and Equipment, Net (Details) (USD $) In Millions, unless otherwise specified	11 Months Ended	12 Months Ended																		1 Months Ended	12 Months Ended
	Dec. 31, 2010 Successor [Member]	Dec. 31, 2012 Successor [Member]	Dec. 31, 2011 Successor [Member]	Dec. 31, 2012 Successor [Member] Property and Equipment under Capital Lease [Member]	Dec. 31, 2011 Successor [Member] Property and Equipment under Capital Lease [Member]	Dec. 31, 2012 Successor [Member] Land [Member]	Dec. 31, 2011 Successor [Member] Land [Member]	Dec. 31, 2012 Successor [Member] Track Structure [Member]	Dec. 31, 2011 Successor [Member] Track Structure [Member]	Dec. 31, 2012 Successor [Member] Other Roadway [Member]	Dec. 31, 2011 Successor [Member] Other Roadway [Member]	Dec. 31, 2012 Successor [Member] Locomotives [Member]	Dec. 31, 2011 Successor [Member] Locomotives [Member]	Dec. 31, 2012 Successor [Member] Freight Cars and Othe Equipment [Member]	Dec. 31, 2011 Successor [Member] Freight Cars and Othe Equipment [Member]	Dec. 31, 2012 Successor [Member] Computer Equipment [Member]	Dec. 31, 2011 Successor [Member] Computer Equipment [Member]	Dec. 31, 2012 Successor [Member] Construction in Progress [Member]	Dec. 31, 2011 Successor [Member] Construction in Progress [Member]	Feb. 12, 2010 Predecessor [Member]	Dec. 31, 2012 Minimum [Member] Successor [Member] Track Structure [Member]	Dec. 31, 2012 Minimum [Member] Successor [Member] Other Roadway [Member]	Dec. 31, 2012 Minimum [Member] Successor [Member] Locomotives [Member]	Dec. 31, 2012 Minimum [Member] Successor [Member] Freight Cars and Othe Equipment [Member]	Dec. 31, 2012 Minimum [Member] Successor [Member] Computer Equipment [Member]	Dec. 31, 2012 Maximum [Member] Successor [Member] Track Structure [Member]	Dec. 31, 2012 Maximum [Member] Successor [Member] Other Roadway [Member]	Dec. 31, 2012 Maximum [Member] Successor [Member] Locomotives [Member]	Dec. 31, 2012 Maximum [Member] Successor [Member] Freight Cars and Othe Equipment [Member]	Dec. 31, 2012 Maximum [Member] Successor [Member] Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life																					15 years	5 years	5 years	8 years	5 years	50 years	100 years	33 years	37 years	9 years
Property, Plant and Equipment, Gross		$ 51,696	$ 49,103			$ 5,950	$ 5,925	$ 17,319	$ 16,460	$ 20,936	$ 20,300	$ 4,505	$ 3,773	$ 1,744	$ 1,501	$ 279	$ 259	$ 963	$ 885
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment		(1,626)	(1,056)	(269)	(222)
Property, Plant and Equipment, Net		50,070	48,047
Capital Leased Asset, Net		1,001	1,585
Interest Costs Capitalized	$ 13	$ 24	$ 20																	$ 1