CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Net sales	$ 393.6	$ 307.6	$ 762.4	$ 603.4
Cost of sales	277.8	203.0	521.5	397.1
Gross profit	115.8	104.6	240.9	206.3
Operating expenses:
Selling, general and administrative	89.4	74.0	181.5	146.7
Other	4.3	3.1	5.3	4.4
Total operating expenses	93.7	77.1	186.8	151.1
Operating income	22.1	27.5	54.1	55.2
Interest expense	(7.3)	(16.1)	(15.5)	(31.0)
Interest income	0.2	0.0	0.6	0.1
Other expense	(1.2)	(0.2)	(0.6)	(3.7)
Income before income taxes	13.8	11.2	38.6	20.6
Income tax expense	(3.9)	(2.2)	(16.1)	(5.2)
Net income	9.9	9.0	22.5	15.4
Comprehensive income	$ 0.0	$ 19.7	$ 22.4	$ 30.8
Basic earnings per share (in dollars per share)	$ 0.47	$ 0.42	$ 1.06	$ 0.72
Diluted earnings per share (in dollars per share)	0.47	0.41	1.05	0.71
Cash dividends per share (in dollars per share)	$ 0.24	$ 0.22	$ 0.48	$ 0.44