Shareholders' Equity Stock Options (Details) (Employee Stock Option [Member], USD $) Share data in Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Jan. 03, 2015		Dec. 28, 2013		Dec. 29, 2012
Employee Stock Option [Member]
Stock options activity [Roll Forward]
Stock options - outstanding beginning of period	1,754
Stock options - granted during period	201
Stock options - exercised during period	(244)
Stock options - canceled/forfeited during period	(198)
Stock options - outstanding end of period	1,513		1,754
Stock options - exercisable at end of period	1,088
Vested and expected to vest - outstanding	1,455
Weighted- Average Exercise Price per Share
Stock options - weighted average exercise price per share, outstanding	$ 15.77
Stock options - weighted average exercise price per share, granted	$ 17.96
Stock options - weighted average exercise price per share, exercised	$ 12.15
Stock options - weighted average exercise price per share, forfeited/canceled	$ 20.19
Stock options - weighted average exercise price per share, outstanding	$ 16.06		$ 15.77
Stock options - weighted average exercise price per share, exercisable	$ 14.32
Stock options - weighted average exercise price per share, vested and expected to vest	$ 15.86
Weighted- Average Remaining Contractual Term
Stock options - weighted average remaining contractual term (years) outstanding	5 years 7 months 6 days		5 years 7 months 6 days
Stock options - weighted average remaining contractual terms (years) exercisable	4 years 6 months
Stock options - weighted average remaining contractual term (years) vested and expected to vest	5 years 6 months
Aggregate Intrinsic Value
Stock options - aggregate intrinsic value outstanding	$ 16,642,000	[1]	$ 11,812,000	[1]
Stock options - aggregate intrinsic value exercisable	13,800,000	[1]
Stock options - aggregate intrinsic value vested and expected to vest	16,279,000	[1]
Other information - options [Abstract]
Weighted-average grant date fair value of stock options granted	$ 9.33		$ 10.57		$ 14.28
Total intrinsic value (at exercise) of stock options exercised	2,478,000		7,726,000		12,724,000
Proceeds from stock options exercised	2,900,000
Tax benefit, exercise of stock options	1,000,000
Stock-based compensation expense related to non-vested awards	$ 2,900,000
Weighted average period to recognize remaining expense over	1 year 7 months 6 days
Stock Option Valuation Assumptions [Abstract]
Fair value assumptions, method used	Black-Scholes-Merton option-pricing model
Expected dividend yield (in hundredths)	0.00%		0.00%		0.00%
Expected volatility (in hundredths)	58.00%		61.00%		63.00%
Risk-free interest rate (in hundredths)	1.80%		0.90%		1.10%
Expected term (in years)	5 years 3 months 18 days		5 years 8 months 12 days		5 years 7 months 6 days

[1] Aggregate intrinsic value includes only those options where the current share price is equal to or greater than the share price on the date of grant.