Deferred Income Tax - Summary of Movement in Net Deferred Income Tax Liability (Parenthetical) (Detail) - EUR (€) € in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Changes in deferred tax liability (asset) [Abstract]
Expense relating to discontinued operations	€ 1	€ 2

Relates to the expense relating to disconitnued operations which is included in net income for the year in movement in net deferred income tax liability.

No definition available.

Name:	crh_ExpenseRelatingToDiscontinuedOperations
Namespace Prefix:	crh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration