Statement Of Changes In Equity [Abstract]
| Concept |
As at 2022-04-02 |
As at 2022-04-02 |
As at 2022-04-02 |
As at 2022-04-02 |
2021-04-04 to 2022-04-02 |
As at 2022-04-02 |
As at 2022-04-02 |
2021-04-04 to 2022-04-02 |
2021-04-04 to 2022-04-02 |
2021-04-04 to 2022-04-02 |
2021-04-04 to 2022-04-02 |
2021-04-04 to 2022-04-02 |
As at 2021-04-03 |
As at 2021-04-03 |
2020-03-29 to 2021-04-03 |
2020-03-29 to 2021-04-03 |
2020-03-29 to 2021-04-03 |
2020-03-29 to 2021-04-03 |
As at 2021-04-03 |
2020-03-29 to 2021-04-03 |
2020-03-29 to 2021-04-03 |
As at 2021-04-03 |
As at 2021-04-03 |
As at 2021-04-03 |
As at 2020-03-28 |
As at 2020-03-28 |
As at 2020-03-28 |
As at 2020-03-28 |
As at 2020-03-28 |
As at 2020-03-28 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity [abstract] | ||||||||||||||||||||||||||||||
| Statement of changes in equity [line items] | ||||||||||||||||||||||||||||||
| Equity |
351,700,000
GBP
|
9,300,000
GBP
|
1,076,700,000
GBP
|
1,500,000
GBP
|
— |
86,300,000
GBP
|
1,506,900,000
GBP
|
— | — | — | — | — |
9,300,000
GBP
|
755,100,000
GBP
|
— | — | — | — |
351,700,000
GBP
|
— | — |
1,183,600,000
GBP
|
85,500,000
GBP
|
600,000
GBP
|
1,680,000,000
GBP
|
1,409,400,000
GBP
|
84,800,000
GBP
|
156,600,000
GBP
|
9,300,000
GBP
|
351,700,000
GBP
|
| Changes in equity [abstract] | ||||||||||||||||||||||||||||||
| Comprehensive income [abstract] | ||||||||||||||||||||||||||||||
| Profit (loss) | — | — | — | — |
–
GBP
|
— | — |
–
GBP
|
77,500,000
GBP
|
–
GBP
|
77,500,000
GBP
|
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
106,000,000
GBP
|
–
GBP
|
— |
106,000,000
GBP
|
–
GBP
|
— | — | — | — | — | — | — | — | — |
| Other comprehensive income | — | — | — | — |
–
GBP
|
— | — |
–
GBP
|
249,100,000
GBP
|
–
GBP
|
249,100,000
GBP
|
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
609,200,000
GBP
|
–
GBP
|
— |
609,200,000
GBP
|
–
GBP
|
— | — | — | — | — | — | — | — | — |
| Comprehensive income | — | — | — | — |
–
GBP
|
— | — |
–
GBP
|
326,600,000
GBP
|
–
GBP
|
326,600,000
GBP
|
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
503,200,000
GBP
|
–
GBP
|
— |
503,200,000
GBP
|
–
GBP
|
— | — | — | — | — | — | — | — | — |
| Issue of equity | — | — | — | — |
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
900,000
GBP
|
1,700,000
GBP
|
800,000
GBP
|
— | — |
–
GBP
|
–
GBP
|
–
GBP
|
1,000,000
GBP
|
— |
1,700,000
GBP
|
700,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Dividends recognised as distributions to owners | — | — | — | — |
–
GBP
|
— | — |
–
GBP
|
8,500,000
GBP
|
–
GBP
|
8,500,000
GBP
|
–
GBP
|
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| Increase (decrease) through share-based payment transactions, equity | — | — | — | — |
–
GBP
|
— | — |
–
GBP
|
3,400,000
GBP
|
–
GBP
|
3,400,000
GBP
|
–
GBP
|
— | — |
–
GBP
|
–
GBP
|
3,100,000
GBP
|
–
GBP
|
— |
3,100,000
GBP
|
–
GBP
|
— | — | — | — | — | — | — | — | — |