EMPLOYEE BENEFITS - DEFINED CONTRIBUTION PENSION SCHEME - Narratives (Details)	Dec. 31, 2020
EMPLOYEE BENEFITS [abstract]
Percentage of standard salary set by provincial government in defined contribution pension scheme	26.00%
Percentage of standard salary borne by the Company or its subsidiaries in defined contribution pension scheme	18.00%
Percentage of standard salary borne by employees in defined contribution pension scheme	8.00%

The percentage of standard salary set by provincial government in defined contribution pension scheme.

No definition available.

Name:	gsh_PercentageOfStandardSalarySetByProvincialGovernmentInDefinedContributionPensionScheme
Namespace Prefix:	gsh_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant