Acquisition (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Dec. 17, 2012 State
Business Acquisition [Line Items]
Number of states serviced			8
Goodwill	$ 22.6	$ 22.8
Indemnity holdback for any post-closing liabilities	4.0
Period of Time to release indemnity holdback	4 years
Contingent payments amount	0.6
Initial capital lease term	10 years
Davenport [Member]
Business Acquisition [Line Items]
Cash paid at closing for acquisition			34.3
Increase of total consideration	1.3
Cash			0.3
Accounts receivable			21.2
Other receivables			3.7
Inventory			20.3
Prepaid expenses / other assets			2.6
Property, plant and equipment			5.9
Intangible assets			2.6
Goodwill			6.5
Net deferred tax liabilities			(1.5)
Capital lease liability	(10.8)		(10.9)
Other liabilities			(10.5)
Total consideration			40.2
Acquisition related costs	0.2
Davenport [Member] | Non-competition agreements [Member]
Business Acquisition [Line Items]
Intangible assets	0.7
Intangible asset, useful life	5 years
Davenport [Member] | Customer relationships [Member]
Business Acquisition [Line Items]
Intangible assets	$ 1.9
Intangible asset, useful life	10 years