Statement Of Changes In Equity [Abstract]

Morgan Sindall Group PLC - Filing #1588159

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	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	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 2020-01-01	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	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	427,100,000 GBP	1,000,000 GBP	—	474,200,000 GBP	—	45,800,000 GBP	—	2,300,000 GBP	—	—	—	373,100,000 GBP	2,300,000 GBP	—	800,000 GBP	45,500,000 GBP	—	420,100,000 GBP	—	—	386,900,000 GBP	800,000 GBP	38,500,000 GBP	396,800,000 GBP	356,800,000 GBP	2,300,000 GBP	2,300,000 GBP	38,500,000 GBP	346,900,000 GBP	386,900,000 GBP	800,000 GBP
Changes in equity [abstract]
Comprehensive income [abstract]
Profit (loss)	—	—	– GBP	—	– GBP	—	– GBP	—	97,900,000 GBP	97,900,000 GBP	45,400,000 GBP	—	—	45,400,000 GBP	—	—	– GBP	—	– GBP	– GBP	—	—	—	—	—	—	—	—	—	—	—
Other comprehensive income	—	—	200,000 GBP	—	– GBP	—	– GBP	—	200,000 GBP	– GBP	– GBP	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—
Comprehensive income	—	—	200,000 GBP	—	– GBP	—	– GBP	—	97,700,000 GBP	97,900,000 GBP	45,400,000 GBP	—	—	45,400,000 GBP	—	—	– GBP	—	– GBP	– GBP	—	—	—	—	—	—	—	—	—	—	—
Issue of equity	—	—	– GBP	—	300,000 GBP	—	– GBP	—	300,000 GBP	– GBP	7,000,000 GBP	—	—	– GBP	—	—	– GBP	—	– GBP	7,000,000 GBP	—	—	—	—	—	—	—	—	—	—	—
Increase (decrease) through share-based payment transactions, equity	—	—	– GBP	—	– GBP	—	– GBP	—	12,100,000 GBP	12,100,000 GBP	100,000 GBP	—	—	100,000 GBP	—	—	– GBP	—	– GBP	– GBP	—	—	—	—	—	—	—	—	—	—	—