| r0.c0 | Costs incurred and recognised profits (less recognised losses)/Current | ifrs-full:CostsIncurredAndRecognisedProfitsLessRecognisedLosses | xbrli:monetaryItemType | instant | ifrs-full:ConsolidatedMember |
| r0.c1 | Costs incurred and recognised profits (less recognised losses)/Previous | ifrs-full:CostsIncurredAndRecognisedProfitsLessRecognisedLosses | xbrli:monetaryItemType | instant | ifrs-full:ConsolidatedMember |
| r1.c0 | Advances received for contracts in progress/Current | ifrs-full:AdvancesReceivedForContractsInProgress | xbrli:monetaryItemType | instant | ifrs-full:ConsolidatedMember |
| r1.c1 | Advances received for contracts in progress/Previous | ifrs-full:AdvancesReceivedForContractsInProgress | xbrli:monetaryItemType | instant | ifrs-full:ConsolidatedMember |
| r2.c0 | Retention for contracts in progress/Current | ifrs-full:RetentionForContractsInProgress | xbrli:monetaryItemType | instant | ifrs-full:ConsolidatedMember |
| r2.c1 | Retention for contracts in progress/Previous | ifrs-full:RetentionForContractsInProgress | xbrli:monetaryItemType | instant | ifrs-full:ConsolidatedMember |
| r3.c0 | Gross amount due from customers for contract work as asset/Current | ifrs-full:GrossAmountDueFromCustomersForContractWorkAsAsset | xbrli:monetaryItemType | instant | ifrs-full:ConsolidatedMember |
| r3.c1 | Gross amount due from customers for contract work as asset/Previous | ifrs-full:GrossAmountDueFromCustomersForContractWorkAsAsset | xbrli:monetaryItemType | instant | ifrs-full:ConsolidatedMember |
| r4.c0 | Gross amount due to customers for contract work as liability/Current | ifrs-full:GrossAmountDueToCustomersForContractWorkAsLiability | xbrli:monetaryItemType | instant | ifrs-full:ConsolidatedMember |
| r4.c1 | Gross amount due to customers for contract work as liability/Previous | ifrs-full:GrossAmountDueToCustomersForContractWorkAsLiability | xbrli:monetaryItemType | instant | ifrs-full:ConsolidatedMember |
| r5.c0 | Progress billings/Current | ifrs-full:ProgressBillings | xbrli:monetaryItemType | instant | ifrs-full:ConsolidatedMember |
| r5.c1 | Progress billings/Previous | ifrs-full:ProgressBillings | xbrli:monetaryItemType | instant | ifrs-full:ConsolidatedMember |
| r6.c0 | Revenue from construction contracts/Current | ifrs-full:RevenueFromConstructionContracts | xbrli:monetaryItemType | duration | ifrs-full:ConsolidatedMember |
| r6.c1 | Revenue from construction contracts/Previous | ifrs-full:RevenueFromConstructionContracts | xbrli:monetaryItemType | duration | ifrs-full:ConsolidatedMember |