XML 122 R90.htm IDEA: XBRL DOCUMENT v3.3.1.900
Stock-Based Compensation - Summary of Fair Value Assumptions, Market Performance Units (Details) - Market Performance RSUs - USD ($)
12 Months Ended
Jan. 31, 2016
Jan. 25, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Weighted average fair value units granted (in dollars per share) $ 0.00  
Chief Executive Officer [Member] | Tranche One    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected lives, in years   1 year 7 months
Estimated volatility   34.00%
Dividend yield   $ 0
Risk-free interest rate   1.50%
Weighted average fair value units granted (in dollars per share) 17.26 $ 17.26
Chief Executive Officer [Member] | Tranche Two    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected lives, in years   2 years 1 month
Estimated volatility   34.00%
Dividend yield   $ 0
Risk-free interest rate   1.50%
Weighted average fair value units granted (in dollars per share) $ 14.88 $ 14.88