Debt Debt Outstanding (Details) (Successor [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Debt Instrument [Line Items]
Total Debt	$ 14,533	[1]	$ 12,665	[1]
Total Debt, Weighted Average Interest Rate	5.50%
Total long-term debt	14,080	[1]	12,139	[1]
Current portion of debt	(453)	[1]	(526)	[1]
Short-term Debt, Weighted Average Interest Rate	5.10%	[1]	5.90%	[1]
Notes and Debentures [Member]
Debt Instrument [Line Items]
Total Debt	12,600	[1]	10,406	[1]
Total Debt, Weighted Average Interest Rate	5.40%	[1]	5.80%	[1]
Equipment Obligations [Member]
Debt Instrument [Line Items]
Total Debt	153	[1]	183	[1]
Total Debt, Weighted Average Interest Rate	5.90%	[1]	6.00%	[1]
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Total Debt	971	[1]	1,140	[1]
Total Debt, Weighted Average Interest Rate	6.00%	[1]	5.90%	[1]
Mortgage Bonds [Member]
Debt Instrument [Line Items]
Total Debt	85	[1]	88	[1]
Total Debt, Weighted Average Interest Rate	4.70%	[1]	4.90%	[1]
Financing Obligation [Member]
Debt Instrument [Line Items]
Total Debt	296	[1]	310	[1]
Total Debt, Weighted Average Interest Rate	6.20%	[1]	6.20%	[1]
Unamortized Fair Value Adjustment [Member]
Debt Instrument [Line Items]
Total Debt	$ 428	[1]	$ 538	[1]

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