Net Income Per Share (Details 1) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Apr. 01, 2017
Potential shares of Cadence's common stock excluded
Total potential common shares excluded	845	784
Long-term performance-based stock awards
Potential shares of Cadence's common stock excluded
Total potential common shares excluded	150	232
Options to purchase shares of common stock
Potential shares of Cadence's common stock excluded
Total potential common shares excluded	416	391
Non-vested shares of restricted stock
Potential shares of Cadence's common stock excluded
Total potential common shares excluded	279	161