Statement Of Changes In Equity [Abstract]

Halma PLC - Filing #2050820

Concept	2023-04-01 to 2024-03-31	As at 2024-03-31	2023-04-01 to 2024-03-31	2023-04-01 to 2024-03-31	As at 2024-03-31	As at 2024-03-31	As at 2024-03-31	2023-04-01 to 2024-03-31	As at 2024-03-31	As at 2024-03-31	As at 2024-03-31	2023-04-01 to 2024-03-31	As at 2024-03-31	As at 2024-03-31	2023-04-01 to 2024-03-31	2023-04-01 to 2024-03-31	2023-04-01 to 2024-03-31	2023-04-01 to 2024-03-31	2023-04-01 to 2024-03-31	2023-04-01 to 2024-03-31	2023-04-01 to 2024-03-31	As at 2024-03-31	As at 2023-03-31	2022-04-01 to 2023-03-31	2022-04-01 to 2023-03-31	2022-04-01 to 2023-03-31	2022-04-01 to 2023-03-31	As at 2023-03-31	As at 2023-03-31	As at 2023-03-31	As at 2023-03-31	2022-04-01 to 2023-03-31	2022-04-01 to 2023-03-31	2022-04-01 to 2023-03-31	2022-04-01 to 2023-03-31	2022-04-01 to 2023-03-31	As at 2023-03-31	As at 2023-03-31	2022-04-01 to 2023-03-31	2022-04-01 to 2023-03-31	As at 2023-03-31	As at 2023-03-31	2022-04-01 to 2023-03-31	As at 2023-03-31	As at 2022-03-31	As at 2022-03-31	As at 2022-03-31	As at 2022-03-31	As at 2022-03-31	As at 2022-03-31	As at 2022-03-31	As at 2022-03-31	As at 2022-03-31	As at 2022-03-31
Statement of changes in equity [abstract]
Statement of changes in equity [line items]
Equity	—	3,200,000 GBP	—	—	1,604,500,000 GBP	– GBP	23,600,000 GBP	—	38,000,000 GBP	58,000,000 GBP	200,000 GBP	—	1,736,500,000 GBP	1,300,000 GBP	—	—	—	—	—	—	—	126,300,000 GBP	600,000 GBP	—	—	—	—	1,598,900,000 GBP	38,000,000 GBP	23,600,000 GBP	46,100,000 GBP	—	—	—	—	—	1,415,800,000 GBP	100,000 GBP	—	—	162,300,000 GBP	200,000 GBP	—	4,400,000 GBP	200,000 GBP	38,000,000 GBP	1,700,000 GBP	30,700,000 GBP	117,100,000 GBP	23,600,000 GBP	1,256,600,000 GBP	1,403,100,000 GBP	400,000 GBP	400,000 GBP
Changes in equity [abstract]
Comprehensive income [abstract]
Profit (loss)	– GBP	—	311,000,000 GBP	42,200,000 GBP	—	—	—	– GBP	—	—	—	268,800,000 GBP	—	—	– GBP	– GBP	– GBP	– GBP	268,800,000 GBP	– GBP	– GBP	—	—	– GBP	288,400,000 GBP	54,100,000 GBP	– GBP	—	—	—	—	– GBP	– GBP	234,500,000 GBP	200,000 GBP	– GBP	—	—	– GBP	– GBP	—	—	234,300,000 GBP	—	—	—	—	—	—	—	—	—	—	—
Other comprehensive income	1,200,000 GBP	—	—	—	—	—	—	1,900,000 GBP	—	—	—	48,100,000 GBP	—	—	– GBP	– GBP	– GBP	– GBP	9,000,000 GBP	– GBP	36,000,000 GBP	—	—	– GBP	—	—	– GBP	—	—	—	—	45,200,000 GBP	– GBP	7,600,000 GBP	100,000 GBP	– GBP	—	—	1,000,000 GBP	6,100,000 GBP	—	—	44,600,000 GBP	—	—	—	—	—	—	—	—	—	—	—
Comprehensive income	1,200,000 GBP	—	—	—	—	—	—	1,900,000 GBP	—	—	—	220,700,000 GBP	—	—	– GBP	– GBP	– GBP	– GBP	259,800,000 GBP	– GBP	36,000,000 GBP	—	—	– GBP	—	—	– GBP	—	—	—	—	45,200,000 GBP	– GBP	226,900,000 GBP	300,000 GBP	– GBP	—	—	1,000,000 GBP	6,100,000 GBP	—	—	278,900,000 GBP	—	—	—	—	—	—	—	—	—	—	—
Dividends recognised as distributions to owners	– GBP	—	—	—	—	—	—	– GBP	—	—	—	78,200,000 GBP	—	—	– GBP	– GBP	– GBP	– GBP	78,200,000 GBP	– GBP	– GBP	—	—	– GBP	—	—	– GBP	—	—	—	—	– GBP	– GBP	73,300,000 GBP	– GBP	– GBP	—	—	– GBP	– GBP	—	—	73,300,000 GBP	—	—	—	—	—	—	—	—	—	—	—
Increase (decrease) through share-based payment transactions, equity	– GBP	—	—	—	—	—	—	– GBP	—	—	—	21,400,000 GBP	—	—	– GBP	– GBP	– GBP	– GBP	21,400,000 GBP	– GBP	– GBP	—	—	– GBP	—	—	– GBP	—	—	—	—	– GBP	– GBP	17,700,000 GBP	– GBP	– GBP	—	—	– GBP	– GBP	—	—	17,700,000 GBP	—	—	—	—	—	—	—	—	—	—	—