Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Sales	$ 924.5	$ 705.3	$ 2,245.1	$ 2,204.1
Cost of sales	714.3	544.8	1,713.7	1,700.2
Gross margin	210.2	160.5	531.4	503.9
Selling and administrative expense	176.7	117.4	407.1	367.6
Operating income	33.5	43.1	124.3	136.3
Interest expense, net	(29.7)	(15.5)	(55.3)	(47.6)
Other income, net	1.5	0.6	12.6	1.4
Income from continuing operations before income taxes	5.3	28.2	81.6	90.1
Income tax expense	(2.7)	(4.6)	(22.5)	(20.8)
Net income from continuing operations	2.6	23.6	59.1	69.3
Income (loss) from discontinued operations, net of income taxes	0.0	19.5	(0.5)	54.2
Net income	2.6	43.1	58.6	123.5
Net income attributable to noncontrolling interests	(0.9)	(0.1)	(1.3)	(0.2)
Net income attributable to Avient common shareholders	$ 1.7	$ 43.0	$ 57.3	$ 123.3
Earnings per share attributable to Avient common shareholders - Basic:
Continuing operations (in USD per share)	$ 0.02	$ 0.31	$ 0.64	$ 0.89
Discontinued operations (in USD per share)	0	0.25	0	0.71
Total (in USD per share)	0.02	0.56	0.64	1.60
Earnings (loss) per share attributable to Avient common shareholders - Diluted:
Continuing operations (in USD per share)	0.02	0.30	0.64	0.89
Discontinued operations (in USD per share)	0	0.26	(0.01)	0.69
Total (in USD per share)	$ 0.02	$ 0.56	$ 0.63	$ 1.58
Weighted-average shares used to compute earnings per common share:
Basic (in shares)	91.5	76.9	89.7	77.3
Plus dilutive impact of share-based compensation (in shares)	0.4	0.5	1.0	0.5
Diluted (in shares)	91.9	77.4	90.7	77.8
Anti-dilutive shares not included in diluted common shares outstanding (in shares)	0.7	0.6	0.9	0.8
Cash dividends declared per share of common stock (in USD per share)	$ 0.2025	$ 0.1950	$ 0.6075	$ 0.5850