Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 50.2	$ 38.8	$ 148.3	$ (95.7)
Other comprehensive income (loss)
Translation adjustments and related hedging instruments	(11.5)	16.0	(27.7)	35.4
Cash flow hedges	0.7	0.0	0.7	0.0
Other	0.0	0.0	0.0	(0.1)
Total comprehensive income (loss)	39.4	54.8	121.3	(60.4)
Comprehensive loss attributable to noncontrolling interests	0.0	0.0	0.1	0.0
Comprehensive income (loss) attributable to PolyOne common shareholders	$ 39.4	$ 54.8	$ 121.4	$ (60.4)