Acquisitions and Divestitures (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Income tax benefit	$ 0	$ (0.5)	$ (0.2)	$ (0.8)
Net loss from discontinued operations	(0.2)	(1.1)	(0.5)	(1.5)
Ready-Mix Concrete Operations
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Revenues	0	0	0	31.6
Loss from discontinued operations before income taxes	(0.2)	(1.6)	(0.7)	(2.3)
Income tax benefit	0	(0.5)	(0.2)	(0.8)
Net loss from discontinued operations	$ (0.2)	$ (1.1)	$ (0.5)	$ (1.5)