XML 85 R66.htm IDEA: XBRL DOCUMENT v3.7.0.1
Schedule of Estimated Fair Value of Options as of Grant Date by Using Black-Scholes Option Pricing Model (Detail) - $ / shares
12 Months Ended
Jan. 28, 2017
Jan. 30, 2016
Jan. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Risk-free interest rate 1.20% 1.50% 1.79%
Dividend yield 1.20% 1.20% 1.20%
Expected volatility factor 23.80% 24.40% 24.20%
Expected option life in years 4 years 9 months 18 days 4 years 6 months 4 years 6 months
Weighted average fair value of options issued $ 14.55 $ 14.48 $ 12.00