Balance Sheet Components - Other Long-term Assets (Details) - USD ($) $ in Thousands	Mar. 29, 2020	Dec. 29, 2019
Balance Sheet Related Disclosures [Abstract]
Equity investments with readily determinable fair value	$ 178,090	$ 173,908
Equity investments without readily determinable fair value	7,481	8,661
Equity investments with fair value option	17,500	17,500
Equity method investments	27,193	26,533
Long-term inventory	56,726	48,214
Other	51,848	56,039
Other long-term assets	$ 338,838	$ 330,855

Equity Investment With Fair Value Option

No definition available.

Name:	spwr_EquityInvestmentWithFairValueOption
Namespace Prefix:	spwr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Equity Method Investments, Other

+ References

No definition available.

+ Details

Name:	spwr_EquityMethodInvestmentsOther
Namespace Prefix:	spwr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Equity investments with readily determinable fair value

+ References

No definition available.

+ Details

Name:	spwr_Equityinvestmentswithreadilydeterminablefairvalue
Namespace Prefix:	spwr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

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

- Definition

Amount of investment in equity security without readily determinable fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=116654751&loc=SL75117539-209714

+ Details

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

- Definition

Inventories not expected to be converted to cash, sold or exchanged within the normal operating cycle.

+ 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 210.5-02.6(d))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Amount of investments, and noncurrent assets classified as other.

+ References

No definition available.

+ Details

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

- Definition

Amount of noncurrent assets classified as other.

+ 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 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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