Segment Reporting (Details 1) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jul. 02, 2011	Jul. 03, 2010	Jan. 01, 2011
Summary of long-lived assets by geography
Total long-lived assets	$ 267,758		$ 285,115
Americas:
United States	238,637		254,113
Other Americas	52		34
Total Americas	238,689		254,147
Segment Reporting (Textuals Abstract)
Number of major customers accounted for 10% or more of Cadence's Revenue	0	0
Total Europe, Middle East and Africa [Member]
Summary of long-lived assets by geography
Long-Lived Assets in Individual Foreign Countries	5,406		6,341
Germany [Member]
Summary of long-lived assets by geography
Long-Lived Assets in Individual Foreign Countries	933		773
Other Europe, Middle East and Africa [Member]
Summary of long-lived assets by geography
Long-Lived Assets in Individual Foreign Countries	4,473		5,568
Japan [Member]
Summary of long-lived assets by geography
Long-Lived Assets in Individual Foreign Countries	4,330		4,532
Total Asia [Member]
Summary of long-lived assets by geography
Long-Lived Assets in Individual Foreign Countries	$ 19,333		$ 20,095