Long-Term Debt - Credit Agreement (Details)			3 Months Ended	6 Months Ended	12 Months Ended
Long-Term Debt - Credit Agreement (Details)	Jun. 06, 2023 USD ($) d	Feb. 24, 2023	Oct. 29, 2023 USD ($)	Jul. 27, 2025 USD ($)	Jan. 26, 2025 USD ($)	Apr. 24, 2025 USD ($)	Apr. 30, 2023 USD ($)	Jan. 29, 2023 USD ($)	Jan. 12, 2023 USD ($)	Nov. 07, 2019 USD ($)
Line of Credit Facility [Line Items]
Proceeds from revolving line of credit					$ 68,300,000
Outstanding balance				$ 527,662,000	$ 562,662,000
Triggering Event Three
Line of Credit Facility [Line Items]
Variable rate spread				4.33%	4.36%
Triggering Event Two
Line of Credit Facility [Line Items]
Variable rate spread					3.58%		3.58%	3.44%
Revolving loans
Line of Credit Facility [Line Items]
Debt instrument margin				1.85%	3.85%
Revolving loans \| Credit Agreement, Matures On January 12, 2028
Line of Credit Facility [Line Items]
Facilities, maximum borrowing capacity									$ 405,000,000
Revolving loans \| Credit Agreement
Line of Credit Facility [Line Items]
Facilities, maximum borrowing capacity						$ 455,000,000.0			600,000,000
Outstanding balance				$ 0	$ 0
Repayments of lines of credit					215,000,000
Undrawn revolving commitments				451,600,000
Maximum amount that can be used to obtain revolving loans and letters of credit in alternative currencies										$ 75,000,000
Debt instrument margin		2.50%
Increase in capacity						$ 117,500,000
Annual amortization	7.50%
Number of days before maturity date if not extended \| d	91
Number of days after maturity date \| d	91
Debt Instrument, Covenant, Non-Extended Notes And Certain Replacement Debt, Threshold	$ 50,000,000
Line Of Credit, Decrease In Maximum Borrowing Capacity	100,000,000
Debt Instrument, Covenant, Minimum Consolidated Liquidity	$ 150,000,000
Revolving loans \| Credit Agreement \| Triggering Event Three
Line of Credit Facility [Line Items]
Debt instrument, covenant, leverage ratio, maximum	8.17
Debt Instrument, Covenant, Liquidity Ratio Required, Minimum	1.66
Revolving loans \| Credit Agreement \| Triggering Event Four
Line of Credit Facility [Line Items]
Debt instrument, covenant, leverage ratio, maximum	10.27
Debt Instrument, Covenant, Liquidity Ratio Required, Minimum	1.40
Revolving loans \| Credit Agreement \| Triggering Event Five
Line of Credit Facility [Line Items]
Debt instrument, covenant, leverage ratio, maximum	10.21
Debt Instrument, Covenant, Liquidity Ratio Required, Minimum	1.37
Revolving loans \| Credit Agreement \| Triggering Event Six
Line of Credit Facility [Line Items]
Debt instrument, covenant, leverage ratio, maximum	9.93
Debt Instrument, Covenant, Liquidity Ratio Required, Minimum	1.41
Revolving loans \| Credit Agreement \| Triggering Event Seven
Line of Credit Facility [Line Items]
Debt instrument, covenant, leverage ratio, maximum	8.42
Debt Instrument, Covenant, Liquidity Ratio Required, Minimum	1.73
Revolving loans \| Credit Agreement \| Triggering Event Eight
Line of Credit Facility [Line Items]
Debt instrument, covenant, leverage ratio, maximum	7.68
Debt Instrument, Covenant, Liquidity Ratio Required, Minimum	1.90
Revolving loans \| Credit Agreement \| Triggering Event Nine
Line of Credit Facility [Line Items]
Debt instrument, covenant, leverage ratio, maximum	6.75
Debt instrument, covenant, leverage ratio, maximum, increase limit	4.25
Debt Instrument, Covenant, Liquidity Ratio Required, Minimum	2.14
Revolving loans \| Credit Agreement \| Triggering Event Ten
Line of Credit Facility [Line Items]
Debt instrument, covenant, leverage ratio, maximum	6.28
Debt Instrument, Covenant, Liquidity Ratio Required, Minimum	2.37
Revolving loans \| Credit Agreement \| Triggering Event Eleven
Line of Credit Facility [Line Items]
Debt instrument, covenant, leverage ratio, maximum	5.81
Debt Instrument, Covenant, Liquidity Ratio Required, Minimum	2.68
Revolving loans \| Credit Agreement \| Triggering Event Twelve
Line of Credit Facility [Line Items]
Debt instrument, covenant, leverage ratio, maximum	5.30
Debt Instrument, Covenant, Liquidity Ratio Required, Minimum	3.01
Revolving loans \| Credit Agreement \| Triggering Event Thirteen
Line of Credit Facility [Line Items]
Debt instrument, covenant, leverage ratio, maximum	3.75
Debt Instrument, Covenant, Liquidity Ratio Required, Minimum	3.50
Revolving loans \| Credit Agreement \| Secured Overnight Financing Rate (SOFR) \| Debt Instrument, One Month Interest Period
Line of Credit Facility [Line Items]
Debt instrument margin	0.11%
Revolving loans \| Credit Agreement \| Secured Overnight Financing Rate (SOFR) \| Debt Instrument, Three Month Interest Period
Line of Credit Facility [Line Items]
Debt instrument margin	0.26%
Revolving loans \| Credit Agreement \| Secured Overnight Financing Rate (SOFR) \| Debt Instrument, Six Month Interest Period
Line of Credit Facility [Line Items]
Debt instrument margin	0.43%
Revolving loans \| Credit Agreement \| Secured Overnight Financing Rate (SOFR) \| Minimum
Line of Credit Facility [Line Items]
Debt instrument margin	1.25%
Revolving loans \| Credit Agreement \| Secured Overnight Financing Rate (SOFR) \| Maximum
Line of Credit Facility [Line Items]
Debt instrument margin	3.75%
Revolving loans \| Credit Agreement \| Base Rate
Line of Credit Facility [Line Items]
Debt instrument margin		1.50%
Revolving loans \| Credit Agreement \| Base Rate \| Minimum
Line of Credit Facility [Line Items]
Debt instrument margin	0.25%
Revolving loans \| Credit Agreement \| Base Rate \| Maximum
Line of Credit Facility [Line Items]
Debt instrument margin	2.75%
Revolving loans \| Credit Agreement, Financial Covenant Relief Period \| Secured Overnight Financing Rate (SOFR) \| Minimum
Line of Credit Facility [Line Items]
Debt instrument margin	3.25%
Revolving loans \| Credit Agreement, Financial Covenant Relief Period \| Base Rate \| Minimum
Line of Credit Facility [Line Items]
Debt instrument margin	2.25%
Secured Debt \| Credit Agreement \| Line of Credit
Line of Credit Facility [Line Items]
Face amount									$ 895,000,000
Outstanding balance				146,212,000	181,212,000
Debt instrument margin	0.10%
Payment on Term Loans in connection with Third Amendment			$ 250,000,000
Debt outstanding				$ 75,000,000.0	$ 150,000,000.0		$ 150,000,000.0	$ 450,000,000
Secured Debt \| Credit Agreement \| Line of Credit \| Triggering Event Two
Line of Credit Facility [Line Items]
Quarterly amortization percentage	1.875%
Secured Debt \| Credit Agreement \| Line of Credit \| Triggering Event One
Line of Credit Facility [Line Items]
Quarterly amortization percentage	1.25%
Letter of Credit \| Credit Agreement
Line of Credit Facility [Line Items]
Facilities, maximum borrowing capacity										40,000,000
Bridge Loan \| Credit Agreement
Line of Credit Facility [Line Items]
Facilities, maximum borrowing capacity										$ 25,000,000

SEMTECH CORP 10-Q