Balance Sheet Components (Schedule Of Available-For-Sale Short-Term) (Details) - USD ($) $ in Thousands	Apr. 03, 2016	Dec. 31, 2015
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Cost	$ 105,188	$ 95,204
Unrealized Gain	39	1
Unrealized Loss	(2)	(65)
Estimated Fair Value	105,225	95,140
U.S. Treasuries [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Cost	105,033	95,057
Unrealized Gain	39	1
Unrealized Loss	(2)	(65)
Estimated Fair Value	105,070	94,993
Certificates Of Deposits [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Cost	155	147
Unrealized Gain	0	0
Unrealized Loss	0	0
Estimated Fair Value	$ 155	$ 147