Net Income Per Share (Details 1) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Potential shares of Cadence's common stock excluded
Total potential common shares excluded	1,519	1,058	1,183	922
Long-term performance-based stock awards
Potential shares of Cadence's common stock excluded
Total potential common shares excluded	0	225	75	229
Options to purchase shares of common stock
Potential shares of Cadence's common stock excluded
Total potential common shares excluded	701	820	559	606
Non-vested shares of restricted stock
Potential shares of Cadence's common stock excluded
Total potential common shares excluded	818	13	549	87