Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Definite-Lived Intangible Assets [Roll Forward]
Beginning Balance		$ 61.0
Amortization		(1.4)	$ (1.4)
Ending Balance		59.6
Accumulated Amortization		16.2		$ 14.8
Estimated Annual Amortization Expense for Definite-Lived Intangible Assets [Abstract]
Remainder of 2018		4.0
2019		4.9
2020		4.7
2021		4.6
2022		4.3
Thereafter		37.1
Intangible Assets [Abstract]
Total Intangible Assets		76.2		$ 77.6
Total Intangible Assets, Amortization		$ (1.4)	$ (1.4)
Weighted Average [Member]
Definite-Lived Intangible Assets [Roll Forward]
Remaining Useful Life (Years)		18 years
Trademarks and Trade Names [Member]
Indefinite-Lived Intangible Assets [Roll Forward]
Beginning Balance		$ 16.6
Ending Balance		16.6
Customer Relationships [Member]
Definite-Lived Intangible Assets [Roll Forward]
Beginning Balance		54.7
Amortization		(1.1)
Ending Balance		$ 53.6
Remaining Useful Life (Years)		20 years
Intangible Assets [Abstract]
Total Intangible Assets, Amortization		$ (1.1)
Developed Technology and Other [Member]
Definite-Lived Intangible Assets [Roll Forward]
Beginning Balance	[1]	6.3
Amortization	[1]	(0.3)
Ending Balance	[1]	6.0
Intangible Assets [Abstract]
Total Intangible Assets, Amortization	[1]	$ (0.3)
Developed Technology and Other [Member] | Minimum [Member]
Definite-Lived Intangible Assets [Roll Forward]
Remaining Useful Life (Years)		1 year
Developed Technology and Other [Member] | Maximum [Member]
Definite-Lived Intangible Assets [Roll Forward]
Remaining Useful Life (Years)		11 years
Developed Technology and Other [Member] | Weighted Average [Member]
Definite-Lived Intangible Assets [Roll Forward]
Remaining Useful Life (Years)		7 years

[1] Developed Technology and Other includes patents, non-compete agreements, land easements and trade names with finite lives.