XML 29 R43.htm IDEA: XBRL DOCUMENT v3.3.0.814
Share-Based Compensation (Restricted Stock Units Assumptions) (Details) - Market-based restricted stock units [Member]
9 Months Ended
Oct. 31, 2015
$ / shares
Nov. 01, 2014
$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Grant date market price (in dollars per share) $ 22.46 $ 38.50
Fair value (in dollars per share) $ 19.04 $ 46.86
Price volatility 45.00% 50.00%
Expected term (years) 2 years 9 months 18 days 2 years 9 months 18 days
Risk-free interest rate 0.90% 0.80%
Dividend yield 3.50% 2.10%
Average volatility of peer companies 34.00% 37.30%
Average correlation coefficient of peer companies 0.3288 0.3786