Goodwill And Intangible Assets (Goodwill And Changes In Carrying Amount Of Goodwill By Operating Segment) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Goodwill [Roll Forward]
Balance, beginning of period	$ 398.1	$ 164.1
Acquisitions of businesses		233.5
Currency translation	(0.1)	0.5
Balance, end of period	398.0	398.1
Global Specialty Engineered Materials [Member]
Goodwill [Roll Forward]
Balance, beginning of period	89.2	82.6
Acquisitions of businesses		6.3
Currency translation	(0.5)	0.3
Balance, end of period	88.7	89.2
Global Color, Additives And Inks [Member]
Goodwill [Roll Forward]
Balance, beginning of period	299.9	72.5
Acquisitions of businesses		227.2
Currency translation	0.4	0.2
Balance, end of period	300.3	299.9
Performance Products And Solutions [Member]
Goodwill [Roll Forward]
Balance, beginning of period	7.4	7.4
Acquisitions of businesses		0
Currency translation	0	0
Balance, end of period	7.4	7.4
PolyOne Distribution [Member]
Goodwill [Roll Forward]
Balance, beginning of period	1.6	1.6
Acquisitions of businesses		0
Currency translation	0	0
Balance, end of period	$ 1.6	$ 1.6