Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands	Jul. 04, 2021	Jan. 03, 2021
Commitments and Contingencies Disclosure [Abstract]
Extended product warranty accrual, current	$ 8,300	$ 9,100
Extended product warranty accrual, noncurrent	2,700	3,100
Unrecognized tax benefits	12,239	12,584
Income tax contingencies	9,500	$ 9,400
Contractual obligation, to be paid, 2021	65,100
Contractual obligation, to be paid, 2022	125,800
Contract liabilities gross of prepayment	74,000
Estimated litigation liability	$ 6,200

Customer Advances and Deposits, Related Party

No definition available.

Name:	spwr_CustomerAdvancesAndDepositsRelatedParty
Namespace Prefix:	spwr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Unrecognized Tax Benefits Including Income Tax Penalties And Interest Accrued

+ References

No definition available.

+ Details

Name:	spwr_UnrecognizedTaxBenefitsIncludingIncomeTaxPenaltiesAndInterestAccrued
Namespace Prefix:	spwr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

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

- Definition

Amount of contractual obligation to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

No definition available.

+ Details

Name:	us-gaap_ContractualObligationDueInNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of contractual obligation to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

No definition available.

+ Details

Name:	us-gaap_ContractualObligationDueInSecondYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount at end of the reporting period of the aggregate extended product warranty liability that is expected to be paid within one year of the balance sheet date or normal operating cycle, if longer. Does not include the balance for the standard product warranty liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_ExtendedProductWarrantyAccrualCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount at end of the reporting period of the aggregate extended product warranty liability that is expected to be paid after one year from the balance sheet date or normal operating cycle, if longer. Does not include the balance for the standard product warranty liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.24)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_ExtendedProductWarrantyAccrualNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of income taxes included in liabilities subject to compromise.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph b
-URI http://asc.fasb.org/extlink&oid=124433192&loc=d3e56015-112765

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=124437977&loc=d3e55717-112764

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56145-112766

+ Details

Name:	us-gaap_LiabilitiesSubjectToCompromiseIncomeTaxContingencies
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Aggregate carrying amount of the estimated litigation liability for known or estimated probable loss from litigation, which may include attorneys' fees and other litigation costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.25)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_LitigationReserve
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant