Statement Of Changes In Equity [Abstract]

FORTERRA PLC - Filing #1590385

Concept	As at 2021-12-31	As at 2021-12-31	2021-01-01 to 2021-12-31	As at 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	As at 2021-12-31	As at 2021-12-31	2021-01-01 to 2021-12-31	As at 2021-12-31	2021-01-01 to 2021-12-31	2021-01-01 to 2021-12-31	2020-01-01 to 2020-12-31	As at 2020-12-31	As at 2020-12-31	2020-01-01 to 2020-12-31	As at 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	As at 2020-12-31	As at 2020-12-31	2020-01-01 to 2020-12-31	2020-01-01 to 2020-12-31	As at 2020-12-31	As at 2019-12-31	As at 2019-12-31	As at 2019-12-31	As at 2019-12-31	As at 2019-12-31	As at 2019-12-31
Statement of changes in equity [abstract]
Statement of changes in equity [line items]
Equity	4,600,000 GBP	213,400,000 GBP	—	23,900,000 GBP	—	—	234,800,000 GBP	200,000 GBP	—	2,300,000 GBP	—	—	—	1 62.3 GBP	– GBP	—	2,300,000 GBP	—	—	2,000,000 GBP	4 1.5 GBP	—	—	204,100,000 GBP	– GBP	156,200,000 GBP	1 57 .8 GBP	3,600,000 GBP	– GBP	2,000,000 GBP
Changes in equity [abstract]
Comprehensive income [abstract]
Profit (loss)	—	—	– GBP	—	– GBP	– GBP	—	—	– GBP	—	45,500,000 GBP	45,500,000 GBP	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—
Other comprehensive income	—	—	200,000 GBP	—	– GBP	– GBP	—	—	– GBP	—	200,000 GBP	– GBP	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—
Comprehensive income	—	—	200,000 GBP	—	– GBP	– GBP	—	—	– GBP	—	45,300,000 GBP	45,500,000 GBP	5,600,000 GBP	—	—	– GBP	—	5,600,000 GBP	– GBP	—	—	– GBP	– GBP	—	—	—	—	—	—	—
Issue of equity	—	—	—	—	—	—	—	—	—	—	—	—	53,000,000 GBP	—	—	– GBP	—	1 1.2 GBP	– GBP	—	—	4 1.5 GBP	300,000 GBP	—	—	—	—	—	—	—
Dividends recognised as distributions to owners	—	—	– GBP	—	– GBP	– GBP	—	—	– GBP	—	1 3. 7 GBP	1 3. 7 GBP	– GBP	—	—	– GBP	—	– GBP	– GBP	—	—	– GBP	– GBP	—	—	—	—	—	—	—
Increase (decrease) through share-based payment transactions, equity	—	—	– GBP	—	– GBP	– GBP	—	—	– GBP	—	2,500,000 GBP	2,500,000 GBP	800,000 GBP	—	—	– GBP	—	800,000 GBP	– GBP	—	—	– GBP	– GBP	—	—	—	—	—	—	—