Debt and Redeemable Preferred Stock - Short-term and Long-term Debt (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Long-term debt due within one year, net
Capital leases due within next twelve months	$ 3.7
Total long-term debt due within one year, net	387.7	$ 2.3
Long-term debt, net
Total long-term debt, net	5.0	354.2
Total debt	392.7	356.5
Senior Secured Notes
Long-term debt due within one year, net
Principal amount outstanding	305.0
Unamortized original issue discount and debt issuance costs	(6.7)
Long-term debt due within one year, net	298.3
Long-term debt, net
Principal amount outstanding		305.0
Unamortized original issue discount and debt issuance costs		(10.1)
Long-term debt, net		294.9
Revolving Credit Facilities
Long-term debt due within one year, net
Principal amount outstanding	86.5
Unamortized debt issuance costs	(0.8)
Long-term debt due within one year, net	85.7
Long-term debt, net
Principal amount outstanding		57.0
Unamortized debt issuance costs		(1.5)
Long-term debt, net		55.5
Term Loan
Long-term debt, net
Term Loan		1.5
Capital Leases
Long-term debt due within one year, net
Capital leases due within next twelve months	3.7	2.3
Long-term debt, net
Capital leases	$ 5.0	$ 2.3