Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies (Details)

 v2.3.0.11
Summary of Significant Accounting Policies (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended
Apr. 30, 2011
May 01, 2010
Fair value of stock option using a Black-Scholes valuation model    
Volatility rate 54.40% 55.00%
Average risk-free interest rate 2.80% 3.10%
Average expected life (in years) 6.3 6.3
Dividend yield 0.00% 0.00%
Summary of Significant Accounting Policies (Textuals) [Abstract]    
Number of shares granted in stock option 45 109
Weighted average fair value of stock option $ 26.11 $ 12.68
Stock compensation expenses $ 2,808 $ 1,735
Unrecognized compensation expense related to unvested options and restricted stock $ 21,279