Commitments and Contingencies - Environmental (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended		3 Months Ended				11 Months Ended	12 Months Ended		1 Months Ended
	Dec. 31, 2012 Successor [Member]	Dec. 31, 2011 Successor [Member]	Sep. 30, 2012 Successor [Member] Environmental Issue	Sep. 30, 2011 Successor [Member] Environmental Issue	Dec. 31, 2010 Successor [Member] Environmental Issue sites	Sep. 30, 2010 Successor [Member] Environmental Issue	Dec. 31, 2010 Successor [Member] Environmental Issue sites	Dec. 31, 2012 Successor [Member] Environmental Issue sites	Dec. 31, 2011 Successor [Member] Environmental Issue	Feb. 12, 2010 Predecessor [Member] Environmental Issue
Loss Contingencies [Line Items]
Number of alleged environmental contamination sites (in sites)								249
Number of environmental superfund sites (in sites)								17
Liability for third-party tort claims								$ 13
Accrued obligations for environmental matters, current liabilities	65	80
Additional Expense Based on Actuarial Study Results			3	29		73
Additional environmental expense due to changes in estimates					100
Number of complex sites					20		20
Reduction in environmental expense due to additional test results						40
Reduction In expense due to settlements of environmental liabilities	30
Estimated time frame for accrued cost distributions	10 years
Future costs for environmental liabilities, minimum								350
Future costs for environmental liabilities, maximum								630
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance							514	570	578	517
Accruals							144	(17)	43	6
Payments							(80)	(95)	(51)	(9)
Ending balance					$ 578		$ 578	$ 458	$ 570	$ 514