Basis of Presentation and New Accounting Standards - Narrative (Details) $ in Thousands			3 Months Ended			6 Months Ended		12 Months Ended
	Sep. 29, 2025 USD ($)	Aug. 14, 2025 USD ($)	Dec. 28, 2025 USD ($) ft² building	Sep. 29, 2025 USD ($)	Sep. 28, 2025 USD ($)	Dec. 28, 2025 USD ($) ft² segment building	Dec. 29, 2024 USD ($)	Jun. 29, 2025 USD ($)	Jun. 22, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reduction of debt, percentage			70.00%			70.00%
Total cash, cash equivalents and short-term investments	$ 835,400		$ 1,292,300	$ 835,400		$ 1,292,300		$ 955,400
Number of reportable segments \| segment						1
Inventory write-off	0		22,800	29,000	$ 29,000		$ 0
Cash tax refunds						$ 698,600		189,100
Deferred AMIC			44,600			44,600		0
Interest income								2,600
Investment tax credit receivable	654,000		72,500	654,000		72,500		653,400
Long-term investment tax credit receivable	$ 181,300		109,500	181,300		109,500		105,000
Increase (decrease) in investment tax credit receivable					$ 50,700
Gain on sale of property			2,400	5,700			$ 800
Net unrealized income (loss) on available-for-sale securities			(400)			$ (400)		(3,800)
Unrealized loss on available-for-sale securities								$ 2,400
Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gain on sale of property				$ 5,700
Building, Build Improvements, Land and Equipment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gain on sale of property			$ 2,400
Building
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of buildings sold \| building			1			1
Idle Property in Durham, NC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Area of land \| ft²			254,000			254,000
Senior Notes \| Senior Secured Notes Due 2030
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of debt held by key debtholders									97.00%
Senior Notes \| Convertible Senior Notes Due 2026
Accounts, Notes, Loans and Financing Receivable [Line Items]
Stated interest rate (as a percent)									1.75%
Senior Notes \| Convertible Senior Notes Due 2028
Accounts, Notes, Loans and Financing Receivable [Line Items]
Stated interest rate (as a percent)									0.25%
Senior Notes \| Convertible Senior Notes Due 2029
Accounts, Notes, Loans and Financing Receivable [Line Items]
Stated interest rate (as a percent)									1.875%
Senior Notes \| Convertible Second-Lien Senior Secured Notes Due 2031
Accounts, Notes, Loans and Financing Receivable [Line Items]
Stated interest rate (as a percent)	2.50%	2.50%		2.50%
Convertible Notes
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of debt held by key debtholders									67.00%
Convertible Notes \| 2L Convertible Notes
Accounts, Notes, Loans and Financing Receivable [Line Items]
Aggregate principal amount		$ 301,130
Non-holdback rights offering, percentage		60.00%
Holdback rights offering, percentage		40.00%
Convertible Notes \| Backstop Premium
Accounts, Notes, Loans and Financing Receivable [Line Items]
Aggregate principal amount	$ 331,400	$ 30,250		$ 331,400
Minimum \| Customer Relationships, Developed Technology & Trade Names
Accounts, Notes, Loans and Financing Receivable [Line Items]
Estimated Useful Life (in Years)			5 years			5 years
Minimum \| Patents
Accounts, Notes, Loans and Financing Receivable [Line Items]
Estimated Useful Life (in Years)			6 months			6 months
Maximum \| Customer Relationships, Developed Technology & Trade Names
Accounts, Notes, Loans and Financing Receivable [Line Items]
Estimated Useful Life (in Years)			11 years			11 years
Maximum \| Patents
Accounts, Notes, Loans and Financing Receivable [Line Items]
Estimated Useful Life (in Years)			23 years			23 years

WOLFSPEED, INC. 10-Q