Share-Based Compensation-Valuation Parameters (Details 1) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jul. 01, 2012	Jun. 30, 2013	Jul. 01, 2012
Employee Stock Option [Member]
Fair value of stock options granted to employees, officers and non-employee board members and ESPP shares granted to employees
Dividend yield	0.00%	0.00%	0.00%	0.00%
Expected volatility	32.00%	40.00%	38.00%	43.00%
Risk-free interest rate	0.72%	0.53%	0.68%	0.61%
Expected term	4 years 4 months	3 years 11 months	4 years 5 months	4 years 4 months
Estimated annual forfeiture rate	8.51%	8.59%	8.51%	8.59%
Weighted average fair value at grant date	$ 16.22	$ 11.34	$ 16.44	$ 16.72
Employee Stock Purchase Plan Shares [Member]
Fair value of stock options granted to employees, officers and non-employee board members and ESPP shares granted to employees
Dividend yield	0.00%	0.00%	0.00%	0.00%
Expected volatility	33.00%	38.00%	33.00%	38.00%
Risk-free interest rate	0.13%	0.15%	0.13%	0.15%
Expected term	0 years 6 months	0 years 6 months	0 years 6 months	0 years 6 months
Weighted average fair value at grant date	$ 12.54	$ 12.24	$ 12.54	$ 12.24