Reportable Segments 2 Parentheticals (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012 Successor [Member]	Jun. 30, 2012 Successor [Member]	Mar. 25, 2012 Predecessor [Member]	Jun. 30, 2011 Predecessor [Member]	Jun. 30, 2011 Predecessor [Member]
Segment Reporting Information [Line Items]
Net reduction in capital accruals	$ 0.2	$ 0.5	$ 13.7	$ 10.4	$ 26.0