CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS’ EQUITY - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjusted Balance	Total Stockholders' Equity	Total Stockholders' Equity Cumulative Effect, Period of Adoption, Adjusted Balance	Preferred Stock	Preferred Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock	Common Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Additional Paid-in Capital	Additional Paid-in Capital Cumulative Effect, Period of Adoption, Adjusted Balance	Treasury Stock	Treasury Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive (Loss) Income	Accumulated Other Comprehensive (Loss) Income Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive (Loss) Income Cumulative Effect, Period of Adoption, Adjusted Balance	Non- controlling Interests	Non- controlling Interests Cumulative Effect, Period of Adoption, Adjusted Balance
Balance at Dec. 31, 2017	$ 2,860.0	$ 2,860.0	$ 2,743.1	$ 2,743.1	$ 0.0	$ 0.0	$ 2.9	$ 2.9	$ 4,032.0	$ 4,032.0	$ (0.1)	$ (0.1)	$ (869.7)	$ (1.3)	$ (871.0)	$ (422.0)	$ 1.3	$ (420.7)	$ 116.9	$ 116.9
Balance (in shares) at Dec. 31, 2017					2,000,000	2,000,000	287,405,939	287,405,939			6,618	6,618
Increase (Decrease) in Stockholders'
Net (loss) income	(319.9)		(324.4)										(324.4)						4.5
Other comprehensive income (loss), net of taxes	(370.7)		(336.2)													(336.2)			(34.5)
Conversion of shares of common stock of PDH into common stock	0.0		9.9						9.9										(9.9)
Conversion of shares of common stock of PDH into common stock (in shares)							793,063
Issuance of common stock under ESPP	1.2		1.2						1.2
Issuance of common stock under ESPP (in shares)							128,595
Equity compensation expense	18.9		18.9						18.9
Exercise/ vesting of share based compensation	(3.3)		(3.3)						0.1		$ (3.4)
Exercise/ vesting of share based compensation (in shares)							988,573				335,349
Changes in non-controlling interests	(5.1)																		(5.1)
Balance at Dec. 31, 2018	2,181.1		2,109.2		$ 0.0		$ 2.9		4,062.1		$ (3.5)		(1,195.4)			(756.9)			71.9
Balance (in shares) at Dec. 31, 2018					2,000,000		289,316,170				341,967
Increase (Decrease) in Stockholders'
Net (loss) income	92.9		92.2										92.2						0.7
Other comprehensive income (loss), net of taxes	27.0		27.0													27.0
Arysta Sale	411.0		457.6						(5.7)							463.3			(46.6)
Conversion of shares of common stock of PDH into common stock	0.0		27.3				$ 0.1		41.1							(13.9)			(27.3)
Conversion of shares of common stock of PDH into common stock (in shares)							4,019,710
Issuance of common stock under ESPP	1.1		1.1						1.1
Issuance of common stock under ESPP (in shares)							123,982
Repurchases of common stock	(507.2)		(507.2)				$ (0.4)				$ (73.5)		(433.3)
Repurchase of common stock (in shares)							(37,000,000)				7,764,242
Equity compensation expense	13.7		13.7						13.7
Exercise/ vesting of share based compensation	0.0								1.9		$ (1.9)
Exercise/ vesting of share based compensation (in shares)							1,968,471				170,989
Changes in non-controlling interests	(0.3)																		(0.3)
Balance at Dec. 31, 2019	2,219.3		2,220.9		$ 0.0		$ 2.6		4,114.2		$ (78.9)		(1,536.5)			(280.5)			(1.6)
Balance (in shares) at Dec. 31, 2019					2,000,000		258,428,333				8,277,198
Increase (Decrease) in Stockholders'
Net (loss) income	75.7		75.7										75.7
Other comprehensive income (loss), net of taxes	85.7		85.7													85.7
Preferred stock conversion (in shares)					(2,000,000)		2,000,000
Issuance of common stock under ESPP	1.1		1.1						1.1
Issuance of common stock under ESPP (in shares)							116,205
Repurchases of common stock	(55.7)		(55.7)								$ (55.7)
Repurchase of common stock (in shares)											5,703,279
Dividends ($0.05 per share)	(12.4)		(12.4)										(12.4)
Equity compensation expense	5.4		5.4						5.4
Exercise/ vesting of share based compensation	(0.9)		(0.9)						2.2		$ (3.1)
Exercise/ vesting of share based compensation (in shares)							785,589				248,803
Changes in non-controlling interests	(0.1)																		(0.1)
Balance at Dec. 31, 2020	$ 2,318.1		$ 2,319.8		$ 0.0		$ 2.6		$ 4,122.9		$ (137.7)		$ (1,473.2)			$ (194.8)			$ (1.7)
Balance (in shares) at Dec. 31, 2020					0		261,330,127				14,229,280