Share-Based Payment Arrangements (Valuation Inputs) (Details)	6 Months Ended
Dec. 31, 2019 GBP (£) £ / shares
2019 Sharesave
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price (in gbp per share) \| £ / shares	£ 31.79
Risk-free rate	2.91%
Expected volatility	36.00%
Expected dividends	0.00%
Fair value of option (in gbp per share) \| £	£ 16.51
2018 Sharesave
Disclosure of terms and conditions of share-based payment arrangement [line items]
Exercise price (in gbp per share) \| £ / shares	£ 24.87
Risk-free rate	2.91%
Expected volatility	36.00%
Expected dividends	0.00%
Fair value of option (in gbp per share) \| £	£ 5.74

The expected volatility of the share price used to calculate the fair value of the share options granted. Expected volatility is a measure of the amount by which a price is expected to fluctuate during a period. The measure of volatility used in option pricing models is the annualised standard deviation of the continuously compounded rates of return on the share over a period of time.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2019-01-01
-Paragraph 47
-Subparagraph a
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-URIDate 2019-03-27

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- Definition

The implied yield currently available on zero-coupon government issues of the country in whose currency the exercise price for share options granted is expressed, with a remaining term equal to the expected term of the option being valued (based on the option's remaining contractual life and taking into account the effects of expected early exercise). [Refer: Government [member]]

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- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

+ References

No definition available.

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- Definition

The exercise price of share options granted.

+ References

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- Definition

The percentage of an expected dividend used to calculate the fair value of share options granted.

+ References

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- Definition

The weighted average fair value of share options granted during the period at the measurement date. [Refer: Weighted average [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2019-01-01
-Paragraph 47
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-URIDate 2019-03-27

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