Statement Of Cash Flows [Abstract]
| Concept |
As at 2023-06-30 |
2022-07-01 to 2023-06-30 |
2021-07-01 to 2022-06-30 |
As at 2022-06-30 |
As at 2021-06-30 |
|---|---|---|---|---|---|
| Statement of cash flows [abstract] | |||||
| Cash flows from (used in) operating activities [abstract] | |||||
| Cash flows from (used in) operations | — |
111,600,000
GBP
|
182,100,000
GBP
|
— | — |
| Income taxes paid (refund), classified as operating activities | — |
7,100,000
GBP
|
24,700,000
GBP
|
— | — |
| Cash flows from (used in) operating activities | — |
104,500,000
GBP
|
157,400,000
GBP
|
— | — |
| Cash flows from (used in) investing activities [abstract] | |||||
| Purchase of property, plant and equipment, classified as investing activities | — |
400,000
GBP
|
500,000
GBP
|
— | — |
| Interest received, classified as investing activities | — |
31,200,000
GBP
|
8,100,000
GBP
|
— | — |
| Cash flows from (used in) investing activities | — |
5,200,000
GBP
|
70,300,000
GBP
|
— | — |
| Cash flows from (used in) financing activities [abstract] | |||||
| Payments to acquire or redeem entity's shares | — |
15,600,000
GBP
|
34,500,000
GBP
|
— | — |
| Payments of lease liabilities, classified as financing activities | — |
2,200,000
GBP
|
2,000,000
GBP
|
— | — |
| Interest paid, classified as financing activities | — |
300,000
GBP
|
400,000
GBP
|
— | — |
| Cash flows from (used in) financing activities | — |
170,700,000
GBP
|
173,300,000
GBP
|
— | — |
| Increase (decrease) in cash and cash equivalents before effect of exchange rate changes | — |
71,400,000
GBP
|
54,400,000
GBP
|
— | — |
| Effect of exchange rate changes on cash and cash equivalents [abstract] | |||||
| Effect of exchange rate changes on cash and cash equivalents | — |
2,000,000
GBP
|
41,500,000
GBP
|
— | — |
| Cash and cash equivalents |
478,600,000
GBP
|
— | — |
552,000,000
GBP
|
456,100,000
GBP
|