Note 9 - Stock-based Compensation - Share Based Compensation Performance Shares Award Outstanding (Details) - Performance Shares [Member] shares in Thousands	6 Months Ended
Jul. 03, 2021 shares
Balance, Shares (in shares)	1,021
Granted, Shares (in shares)	607
Effect of vesting multiplier, Shares (in shares)	55
Vested, Shares (in shares)	(110)
Balance, Shares (in shares)	1,573

The number of shares awarded and vested due to the effect of the vesting multiplier during the period on stock (or unit) option and non-option instrument plans.

No definition available.

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Namespace Prefix:	lscc_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration