Stock-Based Compensation (Stock Option Activity Under The Principal Option Plans) (Details) - Stock Options And Awards - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Dec. 28, 2014	Mar. 29, 2015
Number of Options Outstanding (in shares)
Number of shares, outstanding at beginning of period (shares)		2,349,447
Number of shares, granted (shares)		252,260
Number of shares, exercised (shares)		(11,005)
Number of shares, forfeited or expired (shares)		(85,803)
Number of shares, outstanding at end of period (shares)	2,349,447	2,504,899
Number of shares, vested and expected to vest (shares)		2,380,156
Number of shares, exercisable (shares)		1,992,965
Weighted average exercise price
Weighted-average exercise price, outstanding at beginning of period (USD per share)		$ 17.77
Weighted-average exercise price, granted (USD per share)		13.56
Weighted-average exercise price, exercised (USD per share)		9.46
Weighted-average exercise price, forfeited or expired (USD per share)		17.03
Weighted-average exercise price, outstanding at end of period (USD per share)	$ 17.77	17.41
Weighted-average exercise price, vested and expected to vest (USD per share)		17.61
Weighted-average exercise price, exercisable (USD per share)		$ 18.57
Additional Disclosures [Abstract]
Weighted-average remaining contractual term, outstanding at beginning of period in years	3 years 11 months 23 days	4 years 5 months 20 days
Weighted-average remaining contractual term, vested and expected to vest in years		4 years 2 months 16 days
Weighted-average remaining contractual term, exercisable		3 years 3 months 12 days
Aggregate intrinsic value, outstanding at beginning of period		$ 2,716
Aggregate intrinsic value, outstanding at end of period	$ 2,716	936
Aggregate intrinsic value, vested and expected to vest		922
Aggregate intrinsic value, exercisable		$ 692