Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 03, 2020	Sep. 28, 2019	Sep. 29, 2018
Defined Benefit Plan Disclosure
One-time pension settlement charge	$ 121,324	$ 0	$ 0
Profit share expense	21,968	33,250	$ 22,524
Pension Plan
Defined Benefit Plan Disclosure
Total accumulated benefit obligation	868,316	$ 1,235,230
Fair values of plan assets	786,637
Estimated net prior service cost that will be amortized in next fiscal year	6
Estimated net actuarial loss that will be amortized in next fiscal year	19,261
Trust for Unqualified Plan
Defined Benefit Plan Disclosure
Estimated future employer contributions in next fiscal year	5,200
Postretirement Benefit Plan
Defined Benefit Plan Disclosure
Postretirement healh care benefits - plan assets	$ 0
Discount rate	2.30%	3.00%	4.20%
Service cost discount rate	3.10%	4.30%	3.70%
Interest cost discount rate	2.50%	3.80%	2.80%
Assumed annual per capita rate of increase of medical and drug costs for next fiscal year	8.00%
Defined benefit plan, ultimate trend rate	4.50%
Increase in accumulated postretirement benefit obligation due to one percentage point increase in heath care cost trend rate	$ 140
Decrease in accumulated postretirement benefit obligation due to one percentage point decrease in health care cost trend rate	$ 133
Class B Common Stock
Defined Benefit Plan Disclosure
Number of shares owned by the participants under RSP (in shares)	1,519,892
U.S. Plans | Pension Plan
Defined Benefit Plan Disclosure
Pension settlement reduced projected benefit obligation	$ 486,615	$ 0
Pension Settlement reduced fair value of assets	486,615	0
One-time pension settlement charge	121,324
Fair values of plan assets	$ 615,872	$ 1,004,163	$ 878,983
Assumptions for pension expense, average rate of return on plan assets	4.50%	5.30%	7.00%
Postretirement healh care benefits - plan assets	$ 30,887	$ 35,429
Discount rate	3.00%	3.30%	4.30%
Service cost discount rate	3.50%	4.40%	4.20%
Interest cost discount rate	2.90%	4.10%	3.50%
U.S. Plans | Equity | Pension Plan
Defined Benefit Plan Disclosure
Actual Plan Asset Allocations	37.00%	18.00%
U.S. Plans | Fixed income securities | Pension Plan
Defined Benefit Plan Disclosure
Actual Plan Asset Allocations		82.00%
Non-U.S. Plans | Pension Plan
Defined Benefit Plan Disclosure
Pension settlement reduced projected benefit obligation	$ 2,999	$ 0
Pension Settlement reduced fair value of assets	2,999	0
Fair values of plan assets	$ 170,765	$ 166,242	$ 145,641
Assumptions for pension expense, average rate of return on plan assets	2.70%	3.50%	3.50%
Estimated future employer contributions in next fiscal year	$ 8,700
Postretirement healh care benefits - plan assets	$ 3,862	$ 2,575
Discount rate	1.40%	1.60%	2.80%
Service cost discount rate	1.60%	2.90%	2.50%
Interest cost discount rate	1.30%	2.60%	2.20%
Non-U.S. Plans | Equity | Pension Plan
Defined Benefit Plan Disclosure
Actual Plan Asset Allocations	24.00%	25.00%
Assumptions for pension expense, assumed average asset allocation	30.00%
Non-U.S. Plans | Fixed income securities | Pension Plan
Defined Benefit Plan Disclosure
Assumptions for pension expense, assumed average asset allocation	70.00%