Statement Of Changes In Equity [Abstract]

Halma PLC - Filing #6342877

Concept	As at 2025-03-31	2024-04-01 to 2025-03-31	2024-04-01 to 2025-03-31	As at 2025-03-31	2024-04-01 to 2025-03-31	As at 2025-03-31	As at 2025-03-31	As at 2025-03-31	As at 2025-03-31	2024-04-01 to 2025-03-31	As at 2025-03-31	2024-04-01 to 2025-03-31	2024-04-01 to 2025-03-31	As at 2025-03-31	2024-04-01 to 2025-03-31	As at 2025-03-31	2024-04-01 to 2025-03-31	2024-04-01 to 2025-03-31	2024-04-01 to 2025-03-31	As at 2025-03-31	2024-04-01 to 2025-03-31	2024-04-01 to 2025-03-31	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	2023-04-01 to 2024-03-31	As at 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	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	As at 2023-03-31	As at 2023-03-31	As at 2023-03-31	As at 2023-03-31	As at 2023-03-31	As at 2023-03-31	As at 2023-03-31	As at 2023-03-31	As at 2023-03-31
Statement of changes in equity [abstract]
Statement of changes in equity [line items]
Equity	3,300,000 GBP	—	—	1,899,400,000 GBP	—	– GBP	200,000 GBP	23,600,000 GBP	46,900,000 GBP	—	38,000,000 GBP	—	—	1,792,400,000 GBP	—	300,000 GBP	—	—	—	88,500,000 GBP	—	—	—	3,200,000 GBP	—	—	1,604,500,000 GBP	– GBP	23,600,000 GBP	—	38,000,000 GBP	—	58,000,000 GBP	1,736,500,000 GBP	200,000 GBP	1,300,000 GBP	—	—	—	—	—	—	—	126,300,000 GBP	600,000 GBP	1,598,900,000 GBP	23,600,000 GBP	38,000,000 GBP	46,100,000 GBP	200,000 GBP	1,415,800,000 GBP	100,000 GBP	162,300,000 GBP	4,400,000 GBP
Changes in equity [abstract]
Comprehensive income [abstract]
Profit (loss)	—	355,800,000 GBP	59,400,000 GBP	—	296,400,000 GBP	—	—	—	—	296,400,000 GBP	—	– GBP	– GBP	—	– GBP	—	– GBP	– GBP	– GBP	—	– GBP	– GBP	– GBP	—	311,000,000 GBP	42,200,000 GBP	—	—	—	– GBP	—	268,800,000 GBP	—	—	—	—	– GBP	– GBP	– GBP	– GBP	268,800,000 GBP	– GBP	– GBP	—	—	—	—	—	—	—	—	—	—	—
Other comprehensive income	—	—	—	—	64,800,000 GBP	—	—	—	—	22,600,000 GBP	—	– GBP	– GBP	—	– GBP	—	1,600,000 GBP	– GBP	– GBP	—	37,800,000 GBP	6,000,000 GBP	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	—	—	—	—	—	—	—	—	—	—	—
Comprehensive income	—	—	—	—	231,600,000 GBP	—	—	—	—	273,800,000 GBP	—	– GBP	– GBP	—	– GBP	—	1,600,000 GBP	– GBP	– GBP	—	37,800,000 GBP	6,000,000 GBP	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	—	—	—	—	—	—	—	—	—	—	—
Dividends recognised as distributions to owners	—	—	—	—	83,800,000 GBP	—	—	—	—	83,800,000 GBP	—	– GBP	– GBP	—	– GBP	—	– GBP	– GBP	– GBP	—	– GBP	– GBP	– GBP	—	—	—	—	—	—	– GBP	—	78,200,000 GBP	—	—	—	—	– GBP	– GBP	– GBP	– GBP	78,200,000 GBP	– GBP	– GBP	—	—	—	—	—	—	—	—	—	—	—
Increase (decrease) through share-based payment transactions, equity	—	—	—	—	24,800,000 GBP	—	—	—	—	24,800,000 GBP	—	– GBP	– GBP	—	– GBP	—	– GBP	– GBP	– GBP	—	– GBP	– GBP	– GBP	—	—	—	—	—	—	– GBP	—	21,400,000 GBP	—	—	—	—	– GBP	– GBP	– GBP	– GBP	21,400,000 GBP	– GBP	– GBP	—	—	—	—	—	—	—	—	—	—	—