Quarterly Information (Unaudited) - Financial Results by Quarter (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Quarterly Financial Data [Abstract]
Net sales	$ 486.9	$ 481.8	$ 470.0	$ 454.5	$ 433.9	$ 400.6	$ 388.8	$ 365.8	$ 1,893.2	$ 1,589.1	[1]	$ 1,319.1
Gross profit (loss)	(59.3)	(11.8)	33.7	14.5	47.9	41.4	22.5	16.8	(22.9)	131.3	[1]	(6.1)
Net income (loss)	(65.0)	(20.3)	19.4	(0.3)	35.8	20.8	7.1	(15.1)	$ (66.2)	48.6	[1],[2]	$ (252.4)	[2]
Net income (loss) allocated to common stockholders	$ (65.0)	$ (20.3)	$ 17.9	$ (0.3)	$ 33.0	$ 19.1	$ 6.6	$ (15.1)		$ 44.7
Basic earnings (loss) per share (in dollars per share)	$ (0.74)	$ (0.23)	$ 0.20	$ 0.00	$ 0.38	$ 0.22	$ 0.08	$ (0.17)	$ (0.76)	$ 0.51	[1]	$ (2.90)
Diluted earnings (loss) per share (in dollars per share)	$ (0.74)	$ (0.23)	$ 0.20	$ 0.00	$ 0.37	$ 0.22	$ 0.07	$ (0.17)	$ (0.76)	$ 0.51	[1]	$ (2.90)

[1] As adjusted due to the adoption of ASU 2017-07 Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost

[2] As adjusted due to the adoption of ASU 2016-18 "Statement of Cash Flows (Topic 230) Restricted Cash."