XML 97 R91.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Employee Benefit Plans (Assumptions) (Details)
12 Months Ended
Dec. 25, 2019
Dec. 26, 2018
Dec. 27, 2017
Retirement Benefits [Abstract]      
Discount rate used to determine the benefit obligations 2.56% 3.83%  
Discount rate used to determine net period pension costs 3.83% 3.08% 3.31%