Segment Information (Schedule Of Segment Information) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($) segment	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	5
Segment Reporting Information [Line Items]
Sales	$ 847.0	$ 873.1
Operating Income	71.3	70.1
Assets	2,624.4		$ 2,595.1
Color, Additives and Inks
Segment Reporting Information [Line Items]
Sales	201.2	206.0
Operating Income	34.9	33.8
Specialty Engineered Materials
Segment Reporting Information [Line Items]
Sales	128.4	130.6
Operating Income	23.4	23.1
Designed Structures and Solutions
Segment Reporting Information [Line Items]
Sales	108.1	118.7
Operating Income	0.4	3.2
Performance Products and Solutions
Segment Reporting Information [Line Items]
Sales	145.2	155.7
Operating Income	19.7	11.5
PolyOne Distribution
Segment Reporting Information [Line Items]
Sales	264.1	262.1
Operating Income	17.5	15.7
Operating Segments | Color, Additives and Inks
Segment Reporting Information [Line Items]
Sales	204.9	208.5
Assets	956.7		939.5
Operating Segments | Specialty Engineered Materials
Segment Reporting Information [Line Items]
Sales	141.0	141.9
Assets	445.1		353.4
Operating Segments | Designed Structures and Solutions
Segment Reporting Information [Line Items]
Sales	108.5	119.1
Assets	453.7		449.5
Operating Segments | Performance Products and Solutions
Segment Reporting Information [Line Items]
Sales	166.2	175.9
Assets	251.7		237.4
Operating Segments | PolyOne Distribution
Segment Reporting Information [Line Items]
Sales	268.8	265.7
Assets	229.7		200.0
Corporate and eliminations
Segment Reporting Information [Line Items]
Sales	(42.4)	(38.0)
Operating Income	(24.6)	$ (17.2)
Assets	$ 287.5		$ 415.3