Selected Quarterly Financial Data - Summary of Selected Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 179.2	$ 199.6	$ 198.7	$ 175.7	$ 164.4	$ 192.8	$ 197.9	$ 158.8	$ 753.2	$ 713.9	$ 659.6
Gross margin	36.8	41.3	42.2	35.5	35.6	41.4	42.2	32.0	155.8	151.2	133.3
Operating expenses	42.4	38.2	38.1	37.0	33.8	33.6	32.2	28.9	155.7	128.5	119.2
Operating (loss) income	(5.6)	3.1	4.1	(1.5)	1.8	7.8	10.0	3.1	0.1	22.7	14.5
Net (loss) income from continuing operations	(8.9)	1.3	2.3	$ (0.9)	1.1	4.8	5.9	1.5	(6.2)	13.3	29.4
Net (loss) income from discontinued operations	$ (0.9)	$ 0.1	$ (0.1)		$ (1.3)	$ (0.1)	$ 4.5	$ (0.1)	$ (0.9)	$ 3.0	$ (3.4)
Net (loss) income from continuing operations	$ (0.36)	$ 0.05	$ 0.09	$ (0.04)	$ 0.04	$ 0.19	$ 0.23	$ 0.06	$ (0.25)	$ 0.52	$ 1.17
Net (loss) income from discontinued operations	(0.03)				(0.05)		0.18		(0.04)	0.12	(0.14)
Net (loss) income	$ (0.39)	$ 0.05	$ 0.09	$ (0.04)	$ (0.01)	$ 0.19	$ 0.41	$ 0.06	$ (0.29)	$ 0.64	$ 1.04