Selected Quarterly Financial Data (Schedule Of Quarterly Financial Data) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended																	12 Months Ended
	Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Selected Quarterly Financial Data [Line Items]
Sales	$ 775.8	[1]	$ 841.6	[2]	$ 887.1	[3]	$ 873.1	[4]	$ 869.3	[5]	$ 958.4	[6]	$ 1,005.5	[7]	$ 1,002.3	[8]		$ 3,377.6	$ 3,835.5	$ 3,771.2
Gross Margin	156.9	[1]	169.1	[2]	185.7	[3]	169.8	[4]	152.6	[5]	182.6	[6]	184.5	[7]	188.2	[8]		681.5	707.9	662.2
Operating income (loss)	31.3	[1]	69.2	[2]	80.3	[3]	70.1	[4]	(14.3)	[5]	63.6	[6]	49.4	[7]	56.4	[8]		$ 250.9	$ 155.1	$ 231.5
Net income (loss) from continuing operations	3.0	[1]	44.5	[2]	67.0	[3]	30.2	[4]	(15.0)	[5]	32.3	[6]	30.7	[7]	29.2	[8]
Net income (loss) from continuing operations attributable to PolyOne shareholders	$ 3.1	[1]	$ 44.5	[2]	$ 66.8	[3]	$ 30.2	[4]	$ (14.6)	[5]	$ 32.3	[6]	$ 30.9	[7]	$ 29.4	[8]
Basic net income - continuing operations (in usd per share)	$ 0.04	[1],[9]	$ 0.51	[2],[9]	$ 0.75	[3],[9]	$ 0.34	[4],[9]	$ (0.16)	[5],[9]	$ 0.35	[6],[9]	$ 0.33	[7],[9]	$ 0.31	[8],[9]		$ 1.65	$ 0.85	$ 0.98
Diluted net income - continuing operations (in usd per share)	$ 0.04	[1],[9]	$ 0.50	[2],[9]	$ 0.74	[3],[9]	$ 0.34	[4],[9]	$ (0.16)	[5],[9]	$ 0.35	[6],[9]	$ 0.33	[7],[9]	$ 0.31	[8],[9]		$ 1.63	$ 0.83	$ 0.97
Mark-to-market actuarial net losses (gains)	$ 11.6								$ 56.5								$ (44.0)	$ 11.6	$ 56.5
Environmental remediation expense									2.6		$ 5.9
Reimbursement of previously incurred environmental cost									2.1		1.6
Restructuring charges																		41.9	94.1	$ 52.0
Uncertain tax positions			$ (7.5)
Tax benefits on certain foreign investments													$ (5.4)						(15.0)
Payments of Debt Extinguishment Costs																		13.4	$ 0.0	$ 4.6
Plant Closure and Reductions in Force
Selected Quarterly Financial Data [Line Items]
Restructuring charges	10.1		$ 13.7		$ 7.5		$ 10.6		$ 23.2		$ 17.9		$ 35.1		$ 17.9
Debt extinguishment costs | Line of Credit
Selected Quarterly Financial Data [Line Items]
Payments of Debt Extinguishment Costs	16.4																	16.4
7.375% senior notes due 2020
Selected Quarterly Financial Data [Line Items]
Debt repurchase amount	$ 316.6																	$ 316.6
7.375% senior notes due 2020 | Senior Notes
Selected Quarterly Financial Data [Line Items]
Stated interest rate	7.375%								7.375%									7.375%	7.375%
Tax Year 2005-2012 [Member]
Selected Quarterly Financial Data [Line Items]
Foreign tax credit					$ 26.0

[1] Included for the fourth quarter 2015 are: 1) a mark-to-market pension and other post-retirement charge of $11.6 million, 2) employee separation and restructuring costs of $10.1 million and 3) $16.4 million of debt extinguishment costs primarily due to the repayment in full of $316.6 million aggregate principal amount of our 7.375% senior notes due 2020.

[2] Included for the third quarter 2015 are: 1) employee separation and restructuring costs of $13.7 million and 2) a $7.5 million benefit related to the reversal of an uncertain tax position due to the expiration of the statute of limitations.

[3] Included for the second quarter 2015 are: 1) employee separation and restructuring costs of $7.5 million and 2) a $26.0 million tax benefit as a result of amending U.S. federal income tax returns from 2005 to 2012 to use foreign tax credits.

[4] Included for the first quarter 2015 are employee separation and restructuring costs of $10.6 million.

[5] Included for the fourth quarter 2014 are: 1) a mark-to-market pension and other post-retirement charge of $56.5 million, 2) employee separation and restructuring costs of $23.2 million, 3) environmental remediation costs of $2.6 million and 5) a gain related to the reimbursement of previously incurred environmental costs of $2.1 million

[6] Included for the third quarter 2014 are: 1) employee separation and restructuring costs of $17.9 million, 2) environmental remediation costs of $5.9 million and 3) a gain related to the reimbursement of previously incurred environmental costs of

[7] Included for the second quarter 2014 are: 1) employee separation and restructuring costs of $35.1 million and 2) a $5.4 million tax benefit associated with our investments in certain foreign affiliates.

[8] Included for the first quarter 2014 are employee separation and restructuring costs of $17.9 million.

[9] Per share amounts for the quarter and the full year have been computed separately. The sum of the quarterly amounts may not equal the annual amounts presented because of differences in the average shares outstanding during each period.