Note 13 - Employee Benefit Plans (Details Textual) - USD ($) $ in Millions	12 Months Ended
Dec. 28, 2024	Dec. 30, 2023	Dec. 31, 2022
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 2.8	$ 3.1	$ 2.8
Labor And Related Expense, Incentive Compensation	$ 1.6	$ 15.0	$ 25.2

Amount of expense for salary, wage, profit sharing; incentive and equity-based compensation; and other employee benefit.

No definition available.

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