Other Noncurrent Assets - Schedule of Other Noncurrent Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Disclosure Other Non Current Assets Schedule Of Other Non Current Assets [Abstract]
Pension asset	$ 3.3	$ 1.6
Deferred financing costs, net	0.9	1.1
Other	1.1	2.8
Total	$ 5.3	$ 5.5