Segments - Reconciliation of Adjusted EBITDA to Income (Loss) Before Income Taxes (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		0 Months Ended	3 Months Ended	9 Months Ended		0 Months Ended
	Sep. 30, 2014 Successor [Member]	Sep. 30, 2013 Successor [Member]	Sep. 30, 2014 Successor [Member]	Sep. 30, 2013 Successor [Member]	Sep. 30, 2014 Successor [Member] New Dollar Term Loans [Member]	Sep. 30, 2014 Successor [Member] New Dollar Term Loans [Member]	Sep. 30, 2014 Successor [Member] Carlyle Investment Management L.L.C [Member]	Sep. 30, 2013 Successor [Member] Bridge Facility [Member]	Feb. 28, 2014 Successor [Member] Senior Secured Credit Facilities [Member]	Aug. 30, 2012 Debt Commitment Fees [Member] Bridge Facility [Member]	Aug. 30, 2012 Debt Associated Fees [Member] Bridge Facility [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Fair value step up of acquired inventory sold				$ 103.7
Merger and acquisition related costs				28.1
Commitment and associated fee				25.0				21.0		21.0	4.0
Refinancing cost									3.1
Repayment of outstanding debt					100.0
Pre-tax loss on extinguishment amount			6.1			3.0
Losses related to settlement of forward contracts				(19.4)
Pension curtailment gain	6.6		6.6
Required to pay an annual management fee	$ 8.8	$ 11.3	$ 29.5	$ 33.2			$ 3.0