Stockholders' Equity - Preferred Stock (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) shares	Dec. 31, 2016 USD ($)	Dec. 13, 2016 USD ($) shares
Class of Stock [Line Items]
Preferred stock authorized (in shares)	5,000,000
Dividend price (in dollars per share) | $ / shares	$ 22.85
Common stock issued in connection with exchange of PDH common stock (in shares)	1
Gain (loss) on settlement of temporary equity | $	$ 0.0	$ 0.0	$ 103.0
Gain on amendment of Series B Convertible Preferred Stock | $	0.0	0.0	32.9
Non-cash change in fair value of preferred stock redemption liability | $	$ 0.0	$ 0.0	5.0
Series A Preferred Stock To Common Stock
Class of Stock [Line Items]
Preferred stock to common stock conversion ratio	1
Term of optional extension	3 years
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock authorized (in shares)	2,000,000
Preferred stock issued (in shares)	2,000,000	2,000,000
Preferred stock outstanding (in shares)	2,000,000	2,000,000
Series A Preferred Stock | Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends (in shares) | $ / shares	$ 0
Series A Preferred Stock | Founder Entities
Class of Stock [Line Items]
Preferred stock outstanding (in shares)	2,000,000
Redeemable Series B Preferred Stock
Class of Stock [Line Items]
Temporary equity designated (in shares)	600,000			600,000
Series B Preferred Stock | Arysta
Class of Stock [Line Items]
Make whole payment | $				$ 460.0
Convertible preferred stock, number of equity instruments (in shares)				5,500,000
Gain (loss) on settlement of temporary equity | $			103.0
Gain on amendment of Series B Convertible Preferred Stock | $			$ 32.9
Non-cash change in fair value of preferred stock redemption liability | $		$ 5.0