Statement Of Comprehensive Income [Abstract]
| Concept |
2024-04-05 to 2025-03-31 |
2024-04-05 to 2025-03-31 |
2024-04-05 to 2025-03-31 |
2024-04-05 to 2025-03-31 |
2024-04-05 to 2025-03-31 |
2024-04-05 to 2025-03-31 |
2024-04-05 to 2025-03-31 |
2024-04-05 to 2025-03-31 |
2024-04-05 to 2025-03-31 |
2024-04-05 to 2025-03-31 |
2023-04-05 to 2024-04-04 |
2023-04-05 to 2024-04-04 |
2023-04-05 to 2024-04-04 |
2023-04-05 to 2024-04-04 |
2023-04-05 to 2024-04-04 |
2023-04-05 to 2024-04-04 |
2023-04-05 to 2024-04-04 |
2023-04-05 to 2024-04-04 |
2023-04-05 to 2024-04-04 |
2023-04-05 to 2024-04-04 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of comprehensive income [abstract] | ||||||||||||||||||||
| Profit (loss) |
-
GBP
|
2,304,000,000
GBP
|
-
GBP
|
-
GBP
|
-
GBP
|
2,338,000,000
GBP
|
-
GBP
|
-
GBP
|
2,304,000,000
GBP
|
34,000,000
GBP
|
-
GBP
|
-
GBP
|
1,300,000,000
GBP
|
-
GBP
|
1,300,000,000
GBP
|
-
GBP
|
-
GBP
|
-
GBP
|
-
GBP
|
1,300,000,000
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) from investments in equity instruments | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — | — |
5,000,000
GBP
|
— | — | — | — | — |
| Other comprehensive income, before tax, gains (losses) on revaluation of property, plant and equipment, right-of-use assets and intangible assets | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — | — |
-
GBP
|
— | — | — | — | — |
| Other comprehensive income, before tax, gains (losses) on remeasurements of defined benefit plans | — | — | — | — | — |
192,000,000
GBP
|
— | — | — | — | — | — | — | — |
380,000,000
GBP
|
— | — | — | — | — |
| Components of other comprehensive income that will be reclassified to profit or loss, before tax [abstract] | ||||||||||||||||||||
| Cash flow hedges [abstract] | ||||||||||||||||||||
| Gains (losses) on cash flow hedges, before tax | — | — | — | — | — |
30,000,000
GBP
|
— | — | — | — | — | — | — | — |
21,000,000
GBP
|
— | — | — | — | — |
| Reclassification adjustments on cash flow hedges, before tax | — | — | — | — | — |
24,000,000
GBP
|
— | — | — | — | — | — | — | — |
48,000,000
GBP
|
— | — | — | — | — |
| Cost of hedging [abstract] | ||||||||||||||||||||
| Change in value of foreign currency basis spreads [abstract] | ||||||||||||||||||||
| Gains (losses) on change in value of foreign currency basis spreads, before tax | — | — | — | — | — |
8,000,000
GBP
|
— | — | — | — | — | — | — | — |
5,000,000
GBP
|
— | — | — | — | — |
| Reclassification adjustments on change in value of foreign currency basis spreads, before tax | — | — | — | — | — |
5,000,000
GBP
|
— | — | — | — | — | — | — | — |
10,000,000
GBP
|
— | — | — | — | — |
| Financial assets measured at fair value through other comprehensive income [abstract] | ||||||||||||||||||||
| Gains (losses) on financial assets measured at fair value through other comprehensive income, before tax | — | — | — | — | — |
103,000,000
GBP
|
— | — | — | — | — | — | — | — |
8,000,000
GBP
|
— | — | — | — | — |
| Reclassification adjustments on financial assets measured at fair value through other comprehensive income, before tax | — | — | — | — | — |
8,000,000
GBP
|
— | — | — | — | — | — | — | — |
47,000,000
GBP
|
— | — | — | — | — |
| Income tax relating to components of other comprehensive income that will not be reclassified to profit or loss [abstract] | ||||||||||||||||||||
| Income tax relating to investments in equity instruments included in other comprehensive income | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — |
| Income tax relating to changes in revaluation surplus of property, plant and equipment, right-of-use assets and intangible assets included in other comprehensive income | — | — | — | — | — |
-
GBP
|
— | — | — | — | — | — | — | — |
2,000,000
GBP
|
— | — | — | — | — |
| Income tax relating to remeasurements of defined benefit plans included in other comprehensive income | — | — | — | — | — |
48,000,000
GBP
|
— | — | — | — | — | — | — | — |
190,000,000
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 | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — | — |
20,000,000
GBP
|
— | — | — | — | — |
| Income tax relating to change in value of foreign currency basis spreads included in other comprehensive income | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — | — | — | — |
1,000,000
GBP
|
— | — | — | — | — |
| Income tax relating to financial assets measured at fair value through other comprehensive income included in other comprehensive income | — | — | — | — | — |
31,000,000
GBP
|
— | — | — | — | — | — | — | — |
11,000,000
GBP
|
— | — | — | — | — |
| Other comprehensive income | — | — | — | — | — |
222,000,000
GBP
|
— | — | — | — | — | — | — | — |
269,000,000
GBP
|
— | — | — | — | — |
| Comprehensive income |
-
GBP
|
2,160,000,000
GBP
|
1,000,000
GBP
|
-
GBP
|
2,000,000
GBP
|
2,116,000,000
GBP
|
82,000,000
GBP
|
5,000,000
GBP
|
2,082,000,000
GBP
|
34,000,000
GBP
|
2,000,000
GBP
|
49,000,000
GBP
|
1,031,000,000
GBP
|
-
GBP
|
1,031,000,000
GBP
|
-
GBP
|
-
GBP
|
4,000,000
GBP
|
24,000,000
GBP
|
1,110,000,000
GBP
|
| Comprehensive income attributable to [abstract] | ||||||||||||||||||||
| Comprehensive income, attributable to owners of parent | — | — | — | — | — |
2,082,000,000
GBP
|
— | — | — | — | — | — | — | — |
1,031,000,000
GBP
|
— | — | — | — | — |
| Comprehensive income, attributable to non-controlling interests | — | — | — | — | — |
34,000,000
GBP
|
— | — | — | — | — | — | — | — |
-
GBP
|
— | — | — | — | — |