Non-controlling Interests - Summary of Non-Controlling Interest in Subsidiaries (Detail)	Dec. 31, 2017
Republic Cement & Building Materials, Inc. and Republic Cement Land & Resources, Inc (formerly Luzon Continental Land Corporation) [member]
Disclosure of noncontrolling interests [Line Items]
Economic ownership interest held by non-controlling interest	45.00%

Economic ownership interest held by non-controlling interest.

No definition available.

Name:	crh_EconomicOwnershipInterestHeldByNoncontrollingInterest
Namespace Prefix:	crh_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration