Commitments and Contingencies - Environmental Liabilities (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 25, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Environmental Liabilities [Line Items]
Payments for Environmental Liabilities	$ 1	$ 3	$ 3	$ 4
Successor [Member]
Environmental Liabilities [Line Items]
Current		7
Noncurrent		26
Total environmental liabilities		33
Predecessor [Member]
Environmental Liabilities [Line Items]
Current			9
Noncurrent			12
Total environmental liabilities			$ 21