Consolidated Balance Sheets (Successor [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Successor [Member]
Current assets:
Cash and cash equivalents	$ 1,794		$ 1,960
Accounts receivable, net	1,168		1,150
Materials and supplies	800		739
Current portion of deferred income taxes	341		295
Other current assets	77		121
Total current assets	4,180		4,265
Property and equipment, net of accumulated depreciation of $1,626 and $1,056, respectively	50,070		48,047
Goodwill	14,836		14,803
Intangible assets, net	1,114		1,420
Other assets	1,816		1,845
Total assets	72,016		70,380
Current liabilities:
Accounts payable and other current liabilities	3,122		3,143
Long-term debt due within one year	453	[1]	526	[1]
Total current liabilities	3,575		3,669
Deferred income taxes	16,319		15,637
Long-term debt	14,080	[1]	12,139	[1]
Intangible liabilities, net	1,214		1,496
Pension and retiree health and welfare liability	786		769
Casualty and environmental liabilities	750		905
Other liabilities	963		1,016
Total liabilities	37,687		35,631
Commitments and contingencies (see Notes 6, 13 and 14)
Equity:
Member's Equity	34,574		34,952
Accumulated other comprehensive loss	(245)		(203)
Total equity	34,329		34,749
Total liabilities and equity	$ 72,016		$ 70,380

[1] Amounts represent debt outstanding and weighted average effective interest rates for 2012 and 2011, respectively. Maturities are as of December 31, 2012.