Statement Of Comprehensive Income [Abstract]
| Concept |
2021-09-19 to 2022-09-30 |
2021-09-19 to 2022-09-17 |
2021-09-19 to 2022-09-17 |
2021-09-19 to 2022-09-17 |
2021-09-19 to 2022-09-17 |
2021-09-19 to 2022-09-17 |
2021-09-19 to 2022-09-17 |
2021-09-19 to 2022-09-17 |
2021-09-19 to 2022-09-17 |
2020-09-19 to 2021-09-30 |
2020-09-13 to 2021-09-18 |
2020-09-13 to 2021-09-18 |
2020-09-13 to 2021-09-18 |
2020-09-13 to 2021-09-18 |
2020-09-13 to 2021-09-18 |
2020-09-13 to 2021-09-18 |
2020-09-13 to 2021-09-18 |
2020-09-13 to 2021-09-18 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||||||||||
| Profit (loss) | — |
–
GBP
|
–
GBP
|
700,000,000
GBP
|
700,000,000
GBP
|
20,000,000
GBP
|
720,000,000
GBP
|
–
GBP
|
–
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
498,000,000
GBP
|
478,000,000
GBP
|
478,000,000
GBP
|
20,000,000
GBP
|
| Other comprehensive income [abstract] | ||||||||||||||||||
| Components of other comprehensive income that will not be reclassified to profit or loss, before tax [abstract] | ||||||||||||||||||
| Other comprehensive income, before tax, gains (losses) on remeasurements of defined benefit plans | — |
–
GBP
|
–
GBP
|
821,000,000
GBP
|
821,000,000
GBP
|
–
GBP
|
821,000,000
GBP
|
–
GBP
|
–
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
559,000,000
GBP
|
559,000,000
GBP
|
559,000,000
GBP
|
–
GBP
|
| Components of other comprehensive income that will be reclassified to profit or loss, before tax [abstract] | ||||||||||||||||||
| Exchange differences on translation [abstract] | ||||||||||||||||||
| Reclassification adjustments on exchange differences on translation of foreign operations, before tax | — | — | — | — | — | — |
–
GBP
|
— | — | — |
–
GBP
|
6,000,000
GBP
|
–
GBP
|
–
GBP
|
6,000,000
GBP
|
6,000,000
GBP
|
–
GBP
|
–
GBP
|
| Other comprehensive income, before tax, exchange differences on translation of foreign operations |
440,000,000
GBP
|
–
GBP
|
429,000,000
GBP
|
429,000,000
GBP
|
–
GBP
|
11,000,000
GBP
|
440,000,000
GBP
|
–
GBP
|
–
GBP
|
355,000,000
GBP
|
–
GBP
|
355,000,000
GBP
|
–
GBP
|
–
GBP
|
355,000,000
GBP
|
355,000,000
GBP
|
–
GBP
|
–
GBP
|
| Cash flow hedges [abstract] | ||||||||||||||||||
| Gains (losses) on cash flow hedges, before tax | — | — | — | — | — | — |
419,000,000
GBP
|
— | — | — | — | — | — | — |
39,000,000
GBP
|
— | — | — |
| Other comprehensive income, before tax, cash flow hedges | — |
419,000,000
GBP
|
–
GBP
|
419,000,000
GBP
|
–
GBP
|
–
GBP
|
419,000,000
GBP
|
–
GBP
|
–
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
39,000,000
GBP
|
39,000,000
GBP
|
39,000,000
GBP
|
–
GBP
|
–
GBP
|
| Hedges of net investment in foreign operations [abstract] | ||||||||||||||||||
| Gains (losses) on hedges of net investments in foreign operations, before tax | — | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — |
14,000,000
GBP
|
— | — | — |
| Financial assets measured at fair value through other comprehensive income [abstract] | ||||||||||||||||||
| Other comprehensive income, before tax, financial assets measured at fair value through other comprehensive income | — | — | — | — | — | — |
4,000,000
GBP
|
— | — | — | — | — | — | — |
–
GBP
|
— | — | — |
| Income tax relating to components of other comprehensive income that will not be reclassified to profit or loss [abstract] | ||||||||||||||||||
| Income tax relating to remeasurements of defined benefit plans included in other comprehensive income | — |
–
GBP
|
–
GBP
|
198,000,000
GBP
|
198,000,000
GBP
|
–
GBP
|
198,000,000
GBP
|
–
GBP
|
–
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
–
GBP
|
144,000,000
GBP
|
144,000,000
GBP
|
144,000,000
GBP
|
–
GBP
|
| Income tax relating to components of other comprehensive income that will be reclassified to profit or loss [abstract] | ||||||||||||||||||
| Income tax relating to cash flow hedges included in other comprehensive income | — |
28,000,000
GBP
|
–
GBP
|
28,000,000
GBP
|
–
GBP
|
–
GBP
|
28,000,000
GBP
|
–
GBP
|
–
GBP
|
— |
–
GBP
|
–
GBP
|
–
GBP
|
14,000,000
GBP
|
14,000,000
GBP
|
14,000,000
GBP
|
–
GBP
|
–
GBP
|
| Income tax relating to components of other comprehensive income that will be reclassified to profit or loss | — | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — |
–
GBP
|
— | — | — |
| Other comprehensive income | — |
391,000,000
GBP
|
456,000,000
GBP
|
1,519,000,000
GBP
|
669,000,000
GBP
|
11,000,000
GBP
|
1,530,000,000
GBP
|
3,000,000
GBP
|
–
GBP
|
— |
–
GBP
|
357,000,000
GBP
|
–
GBP
|
25,000,000
GBP
|
101,000,000
GBP
|
101,000,000
GBP
|
433,000,000
GBP
|
–
GBP
|
| Comprehensive income | — |
391,000,000
GBP
|
456,000,000
GBP
|
2,219,000,000
GBP
|
1,369,000,000
GBP
|
31,000,000
GBP
|
2,250,000,000
GBP
|
3,000,000
GBP
|
–
GBP
|
— |
–
GBP
|
357,000,000
GBP
|
–
GBP
|
25,000,000
GBP
|
599,000,000
GBP
|
579,000,000
GBP
|
911,000,000
GBP
|
20,000,000
GBP
|
| Comprehensive income attributable to [abstract] | ||||||||||||||||||
| Comprehensive income, attributable to owners of parent | — | — | — | — | — | — |
2,219,000,000
GBP
|
— | — | — | — | — | — | — |
579,000,000
GBP
|
— | — | — |
| Comprehensive income, attributable to non-controlling interests | — | — | — | — | — | — |
31,000,000
GBP
|
— | — | — | — | — | — | — |
20,000,000
GBP
|
— | — | — |