Inventories (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Inventory [Line Items]
Inventories	$ 79.8	$ 81.9
Sugar inventories
Inventory [Line Items]
Inventories	17.2	23.3
Work in process - sugar
Inventory [Line Items]
Inventories	17.2	0.0
Asphalt
Inventory [Line Items]
Inventories	14.3	21.3
Processed rock, portland cement, and sand
Inventory [Line Items]
Inventories	13.3	15.7
Work in process
Inventory [Line Items]
Inventories	3.2	2.8
Retail merchandise
Inventory [Line Items]
Inventories	1.6	1.5
Parts, materials and supplies inventories
Inventory [Line Items]
Inventories	$ 13.0	$ 17.3