Acquisitions and Divestitures (Details Textual) $ in Millions	1 Months Ended	12 Months Ended
	Jun. 30, 2015 USD ($) facility	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($) acquisition	Dec. 31, 2013 USD ($)
Business Acquisition [Line Items]
Gain recognized		$ 8.3	$ 0.0	$ 12.5
Meyer
Business Acquisition [Line Items]
Acquisition-related transaction costs incurred			8.7
Non-recurring additional state income tax expense			$ 1.5
Construction Products Group
Business Acquisition [Line Items]
Number of businesses acquired | acquisition			1
Energy Equipment Group
Business Acquisition [Line Items]
Number of businesses acquired | acquisition			3
Ready-mix concrete operations
Business Acquisition [Line Items]
Gain on sale of ready-mix concrete operations				$ 12.5
Texas, Mississippi, and Louisiana | Galvanizing Business | Construction Products Group
Business Acquisition [Line Items]
Number of facilities sold | facility	6
Gain recognized	$ 8.3