Statement Of Changes In Equity [Abstract]

FORTERRA PLC - Filing #1590385

Concept	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31
Statement of changes in equity [abstract]
Statement of changes in equity [line items]
Increase (decrease) through transfer to statutory reserve, equity	– GBP	– GBP	1 7 .6 GBP	– GBP	– GBP	1 7 .6 GBP	—	—	—	—	—	—
Increase (decrease) through exercise of options, equity	– GBP	1,200,000 GBP	– GBP	– GBP	– GBP	1,200,000 GBP	1. 7 GBP	– GBP	– GBP	– GBP	1. 7 GBP	– GBP
Decrease (increase) through tax on share-based payment transactions, equity	– GBP	– GBP	– GBP	– GBP	400,000 GBP	400,000 GBP	200,000 GBP	– GBP	200,000 GBP	– GBP	– GBP	– GBP
Purchase of treasury shares	– GBP	5,000,000 GBP	– GBP	– GBP	5,000,000 GBP	– GBP	– GBP	– GBP	1,000,000 GBP	– GBP	1,000,000 GBP	– GBP
Sale or issue of treasury shares	– GBP	1,200,000 GBP	– GBP	– GBP	1,200,000 GBP	– GBP	– GBP	– GBP	900,000 GBP	– GBP	900,000 GBP	– GBP