XML 45 R36.htm IDEA: XBRL DOCUMENT
v3.21.2

Investment Securities - Additional Information (Details) | Sep. 30, 2021 USD ($) Security | Dec. 31, 2020 USD ($) Security
--- | --- | ---
Schedule Of Available For Sale Securities [Line Items] |  |
Number of available-for-sale investment securities in continuous unrealized loss position, less than 12 months | 19 | 0
Number of domestic certificates of deposit held | 25 |
Maximum |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Accrued interest receivable on available-for-sale investment securities | $ | $ 100,000 | $ 100,000

X
- Definition Accrued interest receivable on available-for-sale investment securities. + References No definition available. + Details
Name: | dsgn_AccruedInterestReceivableOnAvailableForSaleInvestmentSecurities
Namespace Prefix: | dsgn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of domestic certificates of deposit held. + References No definition available. + Details
Name: | dsgn_NumberOfDomesticCertificatesOfDepositHeld
Namespace Prefix: | dsgn_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without an allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |