Segment Information (Schedule Of Segment Information) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Sales to External Customers	$ 740.2	$ 735.8	$ 2,313.3	$ 2,223.1
Total Sales	740.2	735.8	2,313.3	2,223.1
Segment Operating Income	50.4	42.5	148.4	272.8
Total Assets	2,156.1		2,156.1		2,081.5
Global Specialty Engineered Materials [Member]
Segment Reporting Information [Line Items]
Sales to External Customers	126.9	138.2	385.0	420.0
Total Sales	136.6	147.5	417.5	446.9
Segment Operating Income	13.1	11.0	37.6	37.7
Total Assets	361.8		361.8		349.7
Global Color, Additives And Inks [Member]
Segment Reporting Information [Line Items]
Sales to External Customers	172.2	137.5	546.5	423.0
Total Sales	172.6	138.2	547.6	424.8
Segment Operating Income	16.5	10.9	56.0	34.7
Total Assets	908.0		908.0		914.3
Performance Products And Solutions [Member]
Segment Reporting Information [Line Items]
Sales to External Customers	188.4	206.6	598.2	616.2
Total Sales	207.5	226.4	653.8	676.5
Segment Operating Income	20.8	16.7	60.9	52.3
Total Assets	280.4		280.4		287.0
PolyOne Distribution [Member]
Segment Reporting Information [Line Items]
Sales to External Customers	252.7	253.5	783.6	763.9
Total Sales	254.4	255.0	788.0	767.5
Segment Operating Income	16.4	14.1	49.8	44.1
Total Assets	216.0		216.0		183.5
Corporate And eliminations [Member]
Segment Reporting Information [Line Items]
Sales to External Customers	0	0	0	0
Total Sales	(30.9)	(31.3)	(93.6)	(92.6)
Segment Operating Income	(16.4)	(10.2)	(55.9)	104.0
Total Assets	$ 389.9		$ 389.9		$ 347.0