Note 3 - Revenue From Contracts With Customers - Contract Balance (Details) $ in Thousands	3 Months Ended
Apr. 03, 2021 USD ($)
Contract assets, balance	$ 5,611
Revenues recorded during the period	3,855
Transferred to Accounts receivable or collected	(3,586)
Contract assets, balance	5,880
Contract liabilities, balance	3,068
Accruals for estimated future stock rotation and scrap returns	1,845
Contract liabilities, balance	$ 4,913

No definition available.

Name:	lscc_ContractWithCustomerAssetRevenueRecordedDuringPeriod
Namespace Prefix:	lscc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents accrued for estimated future stock rotation and scrap returns for contract with customer liability.

+ References

No definition available.

+ Details

Name:	lscc_ContractWithCustomerLiabilityAccruedForEstimatedFutureStockRotationAndScrapReturns
Namespace Prefix:	lscc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130549-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121556615&loc=SL49130531-203044

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=121556615&loc=SL49130533-203044

+ Details

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

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130551-203045

+ Details

Name:	us-gaap_ContractWithCustomerAssetReclassifiedToReceivable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121556615&loc=SL49130531-203044

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
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-Section 50
-Paragraph 8
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-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130549-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121556615&loc=SL49130532-203044

+ Details

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