Inventories (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Inventory [Line Items]
Inventories	$ 85.1	$ 81.9
Sugar inventories
Inventory [Line Items]
Inventories	6.3	23.3
Work in process - sugar
Inventory [Line Items]
Inventories	24.6	0
Asphalt
Inventory [Line Items]
Inventories	20.4	21.3
Processed rock, portland cement, and sand
Inventory [Line Items]
Inventories	14.6	15.7
Work in process
Inventory [Line Items]
Inventories	3.0	2.8
Retail merchandise
Inventory [Line Items]
Inventories	1.6	1.5
Parts, materials and supplies inventories
Inventory [Line Items]
Inventories	$ 14.6	$ 17.3