CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Treasury Stock	Accumulated Deficit	Accumulated Other Comprehensive (Loss) Income	Total Stockholders' Equity	Non- controlling Interests
Balance at Dec. 31, 2017	$ 2,860.0	$ 0.0	$ 2.9	$ 4,032.0	$ (0.1)	$ (869.7)	$ (422.0)	$ 2,743.1	$ 116.9
Balance (in shares) at Dec. 31, 2017		2,000,000	287,405,939		6,618
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	49.8					49.3		49.3	0.5
Other comprehensive income (loss), net of taxes	(309.9)
Other comprehensive income, net of taxes	(309.9)						(276.6)	(276.6)	(33.3)
Exercise/ vesting of share based compensation (in shares)			44,549
Conversion of shares of common stock of PDH into common stock				8.6				8.6	(8.6)
Conversion of shares of common stock of PDH into common stock (in shares)			686,610
Issuance of common stock under ESPP	0.6			0.6				0.6
Issuance of common stock under ESPP (in shares)			70,807
Equity compensation expense	7.4			7.4				7.4
Changes in non-controlling interests	(3.5)			0.0					(3.5)
Balance at Jun. 30, 2018	2,604.4	$ 0.0	$ 2.9	4,048.6	$ (0.1)	(821.7)	(697.3)	2,532.4	72.0
Balance (in shares) at Jun. 30, 2018		2,000,000	288,207,905		6,618
Balance at Mar. 31, 2018	2,967.0	$ 0.0	$ 2.9	4,043.6	$ (0.1)	(833.7)	(356.9)	2,855.8	111.2
Balance (in shares) at Mar. 31, 2018		2,000,000	288,115,844		6,618.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	11.8					12.0		12.0	(0.2)
Other comprehensive income (loss), net of taxes	(375.2)
Other comprehensive income, net of taxes	(375.2)						(340.4)	(340.4)	(34.8)
Exercise/ vesting of share based compensation (in shares)			29,549
Conversion of shares of common stock of PDH into common stock				0.4				0.4	(0.4)
Conversion of shares of common stock of PDH into common stock (in shares)			29,069
Issuance of common stock under ESPP	0.3			0.3				0.3
Issuance of common stock under ESPP (in shares)			33,443
Equity compensation expense	4.3			4.3				4.3
Changes in non-controlling interests	(3.8)			0.0					(3.8)
Balance at Jun. 30, 2018	2,604.4	$ 0.0	$ 2.9	4,048.6	$ (0.1)	(821.7)	(697.3)	2,532.4	72.0
Balance (in shares) at Jun. 30, 2018		2,000,000	288,207,905		6,618
Balance at Dec. 31, 2018	2,181.1	$ 0.0	$ 2.9	4,062.1	$ (3.5)	(1,195.4)	(756.9)	2,109.2	71.9
Balance (in shares) at Dec. 31, 2018		2,000,000	289,316,170		341,967
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	25.3					24.7		24.7	0.6
Other comprehensive income (loss), net of taxes	538.7
Other comprehensive income, net of taxes	49.1						49.1	49.1
Arysta Sale	411.0			(5.7)			463.3	457.6	(46.6)
Exercise/ vesting of share based compensation				1.9	$ (1.9)
Exercise/ vesting of share based compensation (in shares)			1,929,518		170,989
Conversion of shares of common stock of PDH into common stock			$ 0.1	41.1			(13.9)	27.3	(27.3)
Conversion of shares of common stock of PDH into common stock (in shares)			4,019,710
Issuance of common stock under ESPP	0.6			0.6				0.6
Issuance of common stock under ESPP (in shares)			58,425
Repurchases of common stock	(445.1)		$ (0.4)		$ (11.4)	(433.3)		(445.1)
Repurchases of common stock (in shares)			(37,000,000)		(1,154,585)
Equity compensation expense	9.4			9.4				9.4
Changes in non-controlling interests	(0.2)								(0.2)
Balance at Jun. 30, 2019	2,231.2	$ 0.0	$ 2.6	4,109.4	$ (16.8)	(1,604.0)	(258.4)	2,232.8	(1.6)
Balance (in shares) at Jun. 30, 2019		2,000,000	258,323,823		1,667,541
Balance at Mar. 31, 2019	2,255.2	$ 0.0	$ 2.6	4,105.1	$ (5.4)	(1,605.5)	(240.1)	2,256.7	(1.5)
Balance (in shares) at Mar. 31, 2019		2,000,000	257,955,093		512,956
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1.4					1.5		1.5	(0.1)
Other comprehensive income (loss), net of taxes	(18.3)
Other comprehensive income, net of taxes	(18.3)						(18.3)	(18.3)
Exercise/ vesting of share based compensation	1.9			1.9				1.9
Exercise/ vesting of share based compensation (in shares)			336,703
Issuance of common stock under ESPP	0.3			0.3				0.3
Issuance of common stock under ESPP (in shares)			32,027
Repurchases of common stock	(11.4)				$ (11.4)			(11.4)
Repurchases of common stock (in shares)					(1,154,585)
Equity compensation expense	2.1			2.1				2.1
Changes in non-controlling interests	0.0								0.0
Balance at Jun. 30, 2019	$ 2,231.2	$ 0.0	$ 2.6	$ 4,109.4	$ (16.8)	$ (1,604.0)	$ (258.4)	$ 2,232.8	$ (1.6)
Balance (in shares) at Jun. 30, 2019		2,000,000	258,323,823		1,667,541