Cash-settled share-based payment provision - Assumptions used to calculate share-based payment expense (Details)	12 Months Ended
Jun. 30, 2018	Jun. 30, 2017
SARs with no CPTs
Share-based payment transaction
Expected volatility	28.61%	20.86%
Expected dividend yield	3.58%	3.42%
SARs with CPTs
Share-based payment transaction
Expected volatility	27.16%	24.45%
Expected dividend yield	3.51%	3.42%
Expected forfeiture rate	5.00%	9.00%
Minimum \| SARs with no CPTs
Share-based payment transaction
Risk - free interest rate	6.88%	7.03%
Minimum \| SARs with no CPTs issued between 2009-2011
Share-based payment transaction
Vesting period	2 years	2 years
Minimum \| SARs with CPTs
Share-based payment transaction
Risk - free interest rate	6.88%	7.03%
Minimum \| SARs with CPTs issued between 2009-2011
Share-based payment transaction
Vesting period	2 years	2 years
Minimum \| SARs with CPTs issued between 2012-2014
Share-based payment transaction
Vesting period	3 years	3 years
Middle \| SARs with no CPTs issued between 2009-2011
Share-based payment transaction
Vesting period	4 years	4 years
Middle \| SARs with CPTs issued between 2009-2011
Share-based payment transaction
Vesting period	4 years	4 years
Middle \| SARs with CPTs issued between 2012-2014
Share-based payment transaction
Vesting period	4 years	4 years
Maximum \| SARs with no CPTs
Share-based payment transaction
Risk - free interest rate	7.09%	8.75%
Maximum \| SARs with no CPTs issued between 2009-2011
Share-based payment transaction
Vesting period	6 years	6 years
Maximum \| SARs with CPTs
Share-based payment transaction
Risk - free interest rate	7.63%	8.75%
Maximum \| SARs with CPTs issued between 2009-2011
Share-based payment transaction
Vesting period	6 years	6 years
Maximum \| SARs with CPTs issued between 2012-2014
Share-based payment transaction
Vesting period	5 years	5 years

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 2017-01-01
-Paragraph 47
-Subparagraph a
-Clause i
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2017-03-01&anchor=para_47_a_i&doctype=Standard
-URIDate 2017-03-09

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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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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.

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

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- Definition

The percentage of expected forfeiture rate used to calculate the fair value of share granted.

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- Definition

The vesting life of awards in a share-based payment arrangement.

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