XML 122 R84.htm IDEA: XBRL DOCUMENT v3.20.1
Postretirement Medical Benefits - Weighted-Average Assumptions Used to Determine Postretirement Benefit Obligations (Details)
Feb. 01, 2020
Feb. 02, 2019
Retirement Benefits [Abstract]    
Discount rate 3.04% 3.00%
Health care cost trend rate assumed for next year 6.50% 6.50%
Ultimate trend rate 5.00% 5.00%