Asset Employed for Continuing Operations for Corporations Reportable Business Segments (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Segment Reporting Asset Reconciling Item [Line Items]
Assets employed, Total	$ 7,499,654	$ 7,464,392	$ 3,356,043
Operating Segments | Mid-America Group
Segment Reporting Asset Reconciling Item [Line Items]
Assets employed, Total	1,343,337	1,290,833	1,311,860
Operating Segments | Southeast Group
Segment Reporting Asset Reconciling Item [Line Items]
Assets employed, Total	601,130	604,044	606,933
Operating Segments | West Group
Segment Reporting Asset Reconciling Item [Line Items]
Assets employed, Total	2,559,411	2,444,400	1,084,291
Operating Segments | Cement
Segment Reporting Asset Reconciling Item [Line Items]
Assets employed, Total	2,413,867	2,451,799
Operating Segments | Magnesia Specialties
Segment Reporting Asset Reconciling Item [Line Items]
Assets employed, Total	148,296	150,359	151,129
Aggregates Business
Segment Reporting Asset Reconciling Item [Line Items]
Assets employed, Total	4,503,878	4,339,277	3,003,084
Corporate
Segment Reporting Asset Reconciling Item [Line Items]
Assets employed, Total	$ 433,613	$ 522,957	$ 201,830