Network Optimization (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013
Restructuring Cost and Reserve [Line Items]
Restructuring costs recorded	$ 0	$ 7.8
Impairment charges on facilities	0	1.5
Restructuring Reserve [Roll Forward]
Balance at December 31, 2012		0.5
Network optimization charges		6.3
Payments		(5.5)
Balance at September 30, 2013	1.3	1.3
Employee Separation
Restructuring Reserve [Roll Forward]
Balance at December 31, 2012		0
Network optimization charges		1.3
Payments		(0.9)
Balance at September 30, 2013	0.4	0.4
Contract Termination and Other Costs
Restructuring Reserve [Roll Forward]
Balance at December 31, 2012		0.5
Network optimization charges		5.0
Payments		(4.6)
Balance at September 30, 2013	$ 0.9	$ 0.9