Name:	gsh_DisclosureOfGoodwillKeyAssumptionsUsedForValueinuseCalculationLineItems
Namespace Prefix:	gsh_
Data Type:	xbrli:stringItemType
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The amount of impairment loss recognised in profit or loss for goodwill applied to the discounted cash flows.

No definition available.

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Data Type:	xbrli:monetaryItemType
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The amount of impairment loss recognised in profit or loss for goodwill in the value-in-use calculation.

No definition available.

Name:	gsh_ImpairmentLossRecognisedAgainstGoodwillDueToLowerBudgetedGrowthRate
Namespace Prefix:	gsh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The discount rate applied to cash flow projections for a cash-generating unit (group of units). [Refer: Cash-generating units [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2018-01-01
-Paragraph 134
-Subparagraph d
-Clause v
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_d_v&doctype=Standard
-URIDate 2018-03-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2018-01-01
-Paragraph 134
-Subparagraph e
-Clause v
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_e_v&doctype=Standard
-URIDate 2018-03-16

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Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The growth rate used to extrapolate cash flow projections beyond the period covered by the most recent budgets/forecasts for a cash-generating unit (group of units). [Refer: Cash-generating units [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2018-01-01
-Paragraph 134
-Subparagraph d
-Clause iv
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_d_iv&doctype=Standard
-URIDate 2018-03-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2018-01-01
-Paragraph 134
-Subparagraph e
-Clause iv
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_e_iv&doctype=Standard
-URIDate 2018-03-16