Statement Of Changes In Equity [Abstract]
| 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 |
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 |
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 2021-10-01 |
As at 2021-10-01 |
As at 2021-10-01 |
As at 2021-10-01 |
As at 2021-10-01 |
As at 2021-10-01 |
As at 2021-10-01 |
As at 2021-10-01 |
As at 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 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 |
2020-10-01 to 2021-09-30 |
As at 2020-10-01 |
As at 2020-10-01 |
As at 2020-10-01 |
As at 2020-10-01 |
As at 2020-10-01 |
As at 2020-10-01 |
As at 2020-10-01 |
As at 2020-10-01 |
As at 2020-09-30 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | |||||||||||||||||||||||||||||||||||||||||||||||||
| Equity |
-
GBP
|
70,200,000
GBP
|
— | — |
71,100,000
GBP
|
— | — |
1,417,300,000
GBP
|
— |
1,151,200,000
GBP
|
48,000,000
GBP
|
241,400,000
GBP
|
— | — | — |
71,800,000
GBP
|
262,500,000
GBP
|
1,005,900,000
GBP
|
76,700,000
GBP
|
1,241,900,000
GBP
|
70,200,000
GBP
|
50,300,000
GBP
|
-
GBP
|
70,100,000
GBP
|
-
GBP
|
70,200,000
GBP
|
76,700,000
GBP
|
— | — |
50,300,000
GBP
|
— |
1,005,900,000
GBP
|
— |
1,241,900,000
GBP
|
— |
262,500,000
GBP
|
70,100,000
GBP
|
— | — | — |
1,156,000,000
GBP
|
2,500,000
GBP
|
50,300,000
GBP
|
70,200,000
GBP
|
68,700,000
GBP
|
880,700,000
GBP
|
261,800,000
GBP
|
37,800,000
GBP
|
1,156,000,000
GBP
|
| Changes in equity [abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||
| Profit (loss) | — | — |
-
GBP
|
-
GBP
|
— |
313,600,000
GBP
|
-
GBP
|
— |
-
GBP
|
— | — | — |
-
GBP
|
-
GBP
|
313,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
-
GBP
|
-
GBP
|
— |
-
GBP
|
— |
-
GBP
|
— |
164,500,000
GBP
|
— | — |
-
GBP
|
164,500,000
GBP
|
-
GBP
|
— | — | — | — | — | — | — | — | — |
| Other comprehensive income | — | — |
-
GBP
|
-
GBP
|
— |
11,600,000
GBP
|
-
GBP
|
— |
-
GBP
|
— | — | — |
-
GBP
|
-
GBP
|
11,600,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
-
GBP
|
-
GBP
|
— |
-
GBP
|
— |
-
GBP
|
— |
7,300,000
GBP
|
— | — |
2,500,000
GBP
|
4,800,000
GBP
|
-
GBP
|
— | — | — | — | — | — | — | — | — |
| Comprehensive income | — | — |
-
GBP
|
-
GBP
|
— |
325,200,000
GBP
|
-
GBP
|
— |
-
GBP
|
— | — | — |
-
GBP
|
-
GBP
|
325,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
-
GBP
|
-
GBP
|
— |
-
GBP
|
— |
-
GBP
|
— |
171,800,000
GBP
|
— | — |
2,500,000
GBP
|
169,300,000
GBP
|
-
GBP
|
— | — | — | — | — | — | — | — | — |
| Dividends recognised as distributions to owners | — | — |
-
GBP
|
-
GBP
|
— |
68,900,000
GBP
|
-
GBP
|
— |
-
GBP
|
— | — | — |
-
GBP
|
-
GBP
|
68,900,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
-
GBP
|
-
GBP
|
— |
-
GBP
|
— |
-
GBP
|
— |
54,600,000
GBP
|
— | — |
-
GBP
|
54,600,000
GBP
|
-
GBP
|
— | — | — | — | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity | — | — |
-
GBP
|
-
GBP
|
— |
9,200,000
GBP
|
-
GBP
|
— |
-
GBP
|
— | — | — |
-
GBP
|
-
GBP
|
9,200,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
-
GBP
|
-
GBP
|
— |
-
GBP
|
— |
-
GBP
|
— |
8,900,000
GBP
|
— | — |
-
GBP
|
8,900,000
GBP
|
-
GBP
|
— | — | — | — | — | — | — | — | — |
| Increase (decrease) in equity | — | — |
-
GBP
|
21,100,000
GBP
|
— |
145,300,000
GBP
|
28,700,000
GBP
|
— |
1,000,000
GBP
|
— | — | — |
-
GBP
|
21,500,000
GBP
|
175,400,000
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — |
-
GBP
|
1,400,000
GBP
|
— |
700,000
GBP
|
— |
-
GBP
|
— |
125,200,000
GBP
|
— | — |
2,500,000
GBP
|
85,900,000
GBP
|
38,900,000
GBP
|
— | — | — | — | — | — | — | — | — |