Debt - 7.125% Senior Notes and $350 Million 2019 Term Loan - Additional Information (Detail) - Predecessor $ in Millions	12 Months Ended
Dec. 31, 2014 USD ($)
Debt Instrument [Line Items]
Debt instrument repurchased, face amount	$ 47.4
Gain (loss) related to write-off of original issuance discount and deferred financing costs	$ 1.9

Amount of gain (loss) from the difference between the repurchase price of a debt instrument initially issued by the entity and the net carrying amount of the debt at the time of its repurchase.

No definition available.

Name:	us-gaap_GainLossOnRepurchaseOfDebtInstrument
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration