Income Taxes (Details 5) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Jan. 01, 2022
Unrecognized Tax Benefits
Unrecognized tax benefits at the beginning of the fiscal year		$ 126,073	$ 130,530	$ 113,021
Unrecognized tax benefits, decrease resulting from prior period tax positions	[1]	(1,401)
Unrecognized tax benefits, increase resulting from prior period tax positions	[1]		2,152	15,414
Gross amount of the increases in unrecognized tax benefits as a result of tax positions taken during the current year		2,565	2,660	5,100
Amount of decreases in unrecognized tax benefits relating the settlements with taxing authorities, including the utilization of tax attributes		(8,000)	0	(270)
Reductions to unrecognized tax benefits resulting from the lapse of the applicable statute of limitations		(24,768)	(7,430)	(2,778)
Unrecognized Tax Benefits, Decrease Resulting from Foreign Currency Translation		(158)	(1,839)
Effect of foreign currency translation				43
Unrecognized tax benefits at the end of the fiscal year		94,311	126,073	130,530
Total amounts of unrecognized tax benefits that, if upon resolution of the uncertain tax positions would reduce Cadence's effective tax rate		93,398	121,415	79,654
Interest and penalties recognized in Income Statements
Interest		2,282	434	1,171
Penalties		267	7	$ (11)
Interest and penalties recognized in Balance Sheets
Interest		4,813	5,133
Penalties		$ 0	$ 0

[1] Includes unrecognized tax benefits of tax positions recorded in connection with acquisitions