Name:	ifrs-full_DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The amount of dividends proposed or declared after the reporting period but before financial statements are authorised for issue. Such dividends are not recognised as a liability at the end of the reporting period because no obligation exists at that time.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 137
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_137_a&doctype=Standard
-URIDate 2019-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 10
-IssueDate 2019-01-01
-Paragraph 13
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=10&code=ifrs-tx-2019-en-r&anchor=para_13&doctype=Standard
-URIDate 2019-03-27

Name:	ifrs-full_DividendsProposedOrDeclaredBeforeFinancialStatementsAuthorisedForIssueButNotRecognisedAsDistributionToOwners
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

The amount, per share, of dividends proposed or declared before financial statements were authorised for issue but not recognised as distribution to owners.

Name:	ifrs-full_DividendsProposedOrDeclaredBeforeFinancialStatementsAuthorisedForIssueButNotRecognisedAsDistributionToOwnersPerShare
Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

For dividends proposed or declared after the reporting period but before financial statements are authorised for issue, the percentage discount on market price to be used for determining number of shares to be issued to participants in the dividend reinvestment plan.

No definition available.

Name:	wbk_DividendsProposedOrDeclaredDiscountOnMarketPriceForDividendReinvestmentPlan
Namespace Prefix:	wbk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

For dividends proposed or declared after the reporting period but before financial statements are authorised for issue, the trading period over which the market price will be used to determine shares to be issued to participants in the dividend reinvestment plan.

No definition available.