Name:	dsgx_ContractWithCustomerAssetIncreaseDecreaseForForeignExchange
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Period Type:	duration

Amount of increase (decrease) in the contract asset during the period from term licenses recognized as revenue during the period, net of amounts transferred to trade receivables.

No definition available.

Name:	dsgx_ContractWithCustomerAssetIncreaseDecreaseForTermLicensesNet
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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

Amount of increase (decrease) in obligation to transfer good or service to customer for which consideration from customer has been received or is due, from movements in foreign exchange.

No definition available.

Name:	dsgx_ContractWithCustomerLiabilityIncreaseDecreaseForForeignExchange
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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

Amount of increase in obligation to transfer good or service to customer for which consideration from customer has been received or is due, from deferral of revenue.

No definition available.

Name:	dsgx_ContractWithCustomerLiabilityIncreaseFromDeferralOfRevenue
Namespace Prefix:	dsgx_
Data Type:	xbrli:monetaryItemType
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Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
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-Section 50
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Period Type:	instant

Amount of decrease in right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time from transfer to receivable due to right to consideration becoming unconditional.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Period Type:	instant

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Period Type:	instant

Amount of increase (decrease) in obligation to transfer good or service to customer for which consideration from customer has been received or is due, from business combination.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
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Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.