Summary of Asset Used in Each of Business Segments (Detail) (USD $) In Thousands, unless otherwise specified	Nov. 30, 2013	May 31, 2013
Segment Reporting, Asset Reconciling Item [Line Items]
Identifiable assets	$ 1,633,091	$ 1,635,825
Segment, Continuing Operations
Segment Reporting, Asset Reconciling Item [Line Items]
Identifiable assets	1,633,091	1,635,825
Segment, Continuing Operations | Cement Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Identifiable assets	1,154,910	1,174,879
Segment, Continuing Operations | Aggregates
Segment Reporting, Asset Reconciling Item [Line Items]
Identifiable assets	158,688	168,255
Segment, Continuing Operations | Concrete
Segment Reporting, Asset Reconciling Item [Line Items]
Identifiable assets	191,439	182,839
Segment, Continuing Operations | Corporate
Segment Reporting, Asset Reconciling Item [Line Items]
Identifiable assets	$ 128,054	$ 109,852