The total amount of investments in joint ventures that are intended to be held for an extended period of time (longer than one operating cycle) and loans due from and receivables due from the joint ventures.

No definition available.

+ Details

Name:	sndk_NotesReceivableAndInvestmentsInRelatedPartiesNoncurrent
Namespace Prefix:	sndk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 40
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481628/310-20-40-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2

+ Details

Name:	us-gaap_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Sum of the carrying amounts as of the balance sheet date of all investments.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 80
-Name Accounting Standards Codification
-Section 55
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480078/944-80-55-14

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 80
-Name Accounting Standards Codification
-Section 55
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480078/944-80-55-9

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(h))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(6))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

+ Details

Name:	us-gaap_Investments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(5)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-5

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(3))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

+ Details

Name:	us-gaap_NotesReceivableNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	dei_LegalEntityAxis=sndk_TheFlashBusinessOfWesternDigitalCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis=us-gaap_EquityMethodInvesteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis=sndk_FlashPartnersLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_RelatedPartyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis=sndk_FlashAllianceLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis=sndk_FlashForwardLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Related Parties and Related Commitments and Contingencies - Schedule of Notes Receivable and Investments in Related Parties (Details) - USD ($) $ in Millions	Dec. 27, 2024	Jun. 28, 2024	Jun. 30, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total notes receivable and investments in Flash Ventures	$ 871	$ 1,001
The Flash Business of Western Digital Corporation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total notes receivable and investments in Flash Ventures		1,001	$ 1,411
Flash Ventures
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total notes receivable and investments in Flash Ventures	871	1,001
Flash Ventures \| The Flash Business of Western Digital Corporation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total notes receivable and investments in Flash Ventures		1,001	1,411
Flash Partners Ltd
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investments	41	148
Flash Partners Ltd \| The Flash Business of Western Digital Corporation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investments		148	160
Flash Partners Ltd \| Related Party
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, related parties	72	1
Flash Partners Ltd \| Related Party \| The Flash Business of Western Digital Corporation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, related parties		1	37
Flash Alliance Ltd
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investments	118	219
Flash Alliance Ltd \| The Flash Business of Western Digital Corporation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investments		219	274
Flash Alliance Ltd \| Related Party
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, related parties	35	5
Flash Alliance Ltd \| Related Party \| The Flash Business of Western Digital Corporation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, related parties		5	48
Flash Forward Ltd
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investments	129	143
Flash Forward Ltd \| The Flash Business of Western Digital Corporation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investments		143	183
Flash Forward Ltd \| Related Party
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, related parties	$ 476	485
Flash Forward Ltd \| Related Party \| The Flash Business of Western Digital Corporation [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable, related parties		$ 485	$ 709