Going Concern (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Principal amount outstanding	$ 86.5		$ 86.5
Net loss	40.5	$ 10.8	58.0	$ 22.0
Net cash used in operating activities			20.6	$ 8.0
Total liquidity	$ 51.2		$ 51.2
Revolving Credit Facilities
Debt Instrument Maturity Date Description			The ABL Facility expires on the earlier of the instrument's expiration date, March 14, 2022, or 90 days prior to the maturity date of the Senior Secured Notes or the Company's Redeemable Preferred Stock, which as of the date that these unaudited financial statements were filed, was October 17, 2018.
Debt, expires prior to current maturity date			90 days
Period in which credit facility due to expire			1 year