Acquisitions - Other Acquisitions (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Goodwill	$ 99.6				$ 102.3	$ 99.6	$ 0
Acquisition related costs	0.1	2.0	1.5	1.0	0	4.6	6.8
Various Acquisitions
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Property, plant and equipment	224.2					224.2
Intangible assets	20.9					20.9
Goodwill	9.3					9.3
Total assets acquired	254.4					254.4
Intangible liabilities	8.3					8.3
Long-term debt, including current portion	134.2					134.2
Total liabilities assumed	142.5					142.5
Net assets acquired	111.9					111.9
The purchase was funded with 1031 proceeds						111.1
Liabilities assumed in a business combination	130.9					130.9
Cash consideration						0.8
Acquisition related costs						2.1
Net revenues since acquisition						12.4
Net earnings (loss) since acquisition						$ 2.1