Statement Of Changes In Equity [Abstract]

Grainger PLC - Filing #1807285

Concept	As at 2022-09-30	As at 2022-09-30	2021-10-01 to 2022-09-30	2021-10-01 to 2022-09-30	As at 2022-09-30	2021-10-01 to 2022-09-30	As at 2022-09-30	2021-10-01 to 2022-09-30	As at 2022-09-30	As at 2022-09-30	2021-10-01 to 2022-09-30	2021-10-01 to 2022-09-30	2021-10-01 to 2022-09-30	As at 2022-09-30	As at 2021-09-30	As at 2021-09-30	2020-10-01 to 2021-09-30	2020-10-01 to 2021-09-30	As at 2021-09-30	2020-10-01 to 2021-09-30	As at 2021-09-30	2020-10-01 to 2021-09-30	As at 2021-09-30	2020-10-01 to 2021-09-30	As at 2021-09-30	As at 2021-09-30	2020-10-01 to 2021-09-30	2020-10-01 to 2021-09-30	As at 2020-09-30	As at 2020-09-30	As at 2020-09-30	As at 2020-09-30	As at 2020-09-30	As at 2020-09-30	As at 2020-09-30
Statement of changes in equity [abstract]
Statement of changes in equity [line items]
Equity	32 .1 GBP	2 0 .1 GBP	—	—	8 17. 6 GBP	—	1, 9 6 6 . 8 GBP	—	1, 0 59 . 6 GBP	3 7.1 GBP	—	—	—	300,000 GBP	3 . 3 GBP	2 0 .1 GBP	—	—	300,000 GBP	—	8 6 7. 5 GBP	—	1, 73 9 . 0 GBP	—	3 7.1 GBP	8 1 7. 3 GBP	—	—	7 8 9 .1 GBP	2 0 .1 GBP	33. 8 GBP	61 6 . 3 GBP	300,000 GBP	1,4 4 3 . 0 GBP	1 6 . 6 GBP
Changes in equity [abstract]
Comprehensive income [abstract]
Profit (loss)	—	—	– GBP	– GBP	—	229. 4 GBP	—	– GBP	—	—	– GBP	– GBP	229 .4 GBP	—	—	—	– GBP	– GBP	—	– GBP	—	– GBP	—	10 9. 5 GBP	—	—	– GBP	10 9 . 5 GBP	—	—	—	—	—	—	—
Other comprehensive income	—	—	35,400,000 GBP	– GBP	—	4,300,000 GBP	—	– GBP	—	—	– GBP	– GBP	39,700,000 GBP	—	—	—	– GBP	– GBP	—	– GBP	—	– GBP	—	4,300,000 GBP	—	—	13 . 3 GBP	1 7. 6 GBP	—	—	—	—	—	—	—
Comprehensive income	—	—	35. 4 GBP	– GBP	—	233,700,000 GBP	—	– GBP	—	—	– GBP	– GBP	2 6 9 .1 GBP	—	—	—	– GBP	– GBP	—	– GBP	—	– GBP	—	11 3 . 8 GBP	—	—	13 . 3 GBP	1 2 7.1 GBP	—	—	—	—	—	—	—
Issue of equity	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	—	– GBP	20 0.8 GBP	—	3,300,000 GBP	—	– GBP	—	– GBP	—	—	– GBP	2 0 4 .1 GBP	—	—	—	—	—	—	—
Dividends recognised as distributions to owners	—	—	– GBP	– GBP	—	4 0. 0 GBP	—	– GBP	—	—	– GBP	– GBP	4 0 . 0 GBP	—	—	—	– GBP	– GBP	—	– GBP	—	– GBP	—	36 .8 GBP	—	—	– GBP	36 .8 GBP	—	—	—	—	—	—	—
Increase (decrease) through share-based payment transactions, equity	—	—	– GBP	– GBP	—	1,700,000 GBP	—	– GBP	—	—	– GBP	– GBP	1,700,000 GBP	—	—	—	– GBP	– GBP	—	– GBP	—	– GBP	—	1,700,000 GBP	—	—	– GBP	1,700,000 GBP	—	—	—	—	—	—	—