Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Sales	$ 711.5	$ 750.6
Cost of sales	540.0	582.5
Gross margin	171.5	168.1
Selling and administrative expense	118.7	121.0
Operating income	52.8	47.1
Interest expense, net	(9.4)	(15.9)
Other income, net	1.6	0.1
Income from continuing operations before income taxes	45.0	31.3
Income tax expense	(11.9)	(8.8)
Net income from continuing operations	33.1	22.5
(Loss) income from discontinued operations, net of income taxes	(0.3)	15.8
Net income	32.8	38.3
Net income attributable to noncontrolling interests	0.0	(0.1)
Net income attributable to PolyOne common shareholders	$ 32.8	$ 38.2
Earnings per share attributable to PolyOne common shareholders - Basic:
Continuing operations (in USD per share)	$ 0.38	$ 0.29
Discontinued operations (in USD per share)	0	0.20
Total (in USD per share)	0.38	0.49
Earnings per share attributable to PolyOne common shareholders - Diluted:
Continuing operations (in USD per share)	0.38	0.29
Discontinued operations (in USD per share)	0	0.20
Total (in USD per share)	$ 0.38	$ 0.49
Weighted-average shares used to compute earnings per common share:
Basic (in shares)	86.3	77.8
Plus dilutive impact of share-based compensation (in shares)	0.4	0.4
Diluted (in shares)	86.7	78.2
Anti-dilutive shares not included in diluted common shares outstanding (in shares)	0.8	0.9
Cash dividends declared per share of common stock (in USD per share)	$ 0.2025	$ 0.1950