Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Oct. 01, 2016
Defined Benefit Plan Disclosure
Employer match percent	25.00%
Percentage match of eligible compensation contributed to investment selection	2.00%
Profit share expense	$ 22,524	$ 26,534	$ 16,656
Pension Plan
Defined Benefit Plan Disclosure
Total accumulated benefit obligation	1,044,579	$ 1,064,195
Fair values of plan assets	1,024,624
Reduction in service and interest costs for annual pension expense in the next fiscal year	7,000
Estimated net prior service cost that will be amortized in next fiscal year	168
Estimated net actuarial loss that will be amortized in next fiscal year	24,470
Trust for Unqualified Plan
Defined Benefit Plan Disclosure
Estimated future employer contributions in next fiscal year	4,500
Postretirement Benefit Plan
Defined Benefit Plan Disclosure
Plan assets	$ 0
Discount rate	4.20%	3.60%	3.20%
Service cost discount rate	3.70%	3.40%
Interest cost discount rate	2.80%	2.50%
Discount rate			3.90%
Assumed annual per capita rate of increase of medical and drug costs for next fiscal year	8.50%
Defined benefit plan, ultimate trend rate	5.00%
Defined benefit plan, year of ultimate trend rate	2026
Increase in accumulated postretirement benefit obligation due to one percentage point increase in heath care cost trend rate	$ 152
Decrease in accumulated postretirement benefit obligation due to one percentage point decrease in health care cost trend rate	$ 144
Class B Common Stock
Defined Benefit Plan Disclosure
Number of shares owned by the participants under RSP (in shares)	1,451,069
U.S. Plans | Pension Plan
Defined Benefit Plan Disclosure
Fair values of plan assets	$ 878,983	$ 756,274	$ 675,018
Assumptions for pension expense, average rate of return on plan assets	7.00%	7.50%	7.70%
Plan assets	$ 49,967	$ 0
Discount rate	4.30%	4.00%	3.80%
Service cost discount rate	4.20%	4.00%
Interest cost discount rate	3.50%	3.20%
Discount rate			4.50%
U.S. Plans | Equity | Pension Plan
Defined Benefit Plan Disclosure
Assumptions for pension expense, assumed rate of return		57.00%
U.S. Plans | Fixed income securities | Pension Plan
Defined Benefit Plan Disclosure
Assumptions for pension expense, assumed rate of return		43.00%
Non-U.S. Plans | Pension Plan
Defined Benefit Plan Disclosure
Fair values of plan assets	$ 145,641	$ 141,906	$ 135,439
Assumptions for pension expense, average rate of return on plan assets	3.50%	3.60%	4.10%
Estimated future employer contributions in next fiscal year	$ 7,700
Plan assets	$ 7,874	$ 1,672
Discount rate	2.80%	2.50%	1.90%
Service cost discount rate	2.50%	2.00%
Interest cost discount rate	2.20%	1.70%
Discount rate			3.00%
Non-U.S. Plans | Equity | Pension Plan
Defined Benefit Plan Disclosure
Assumptions for pension expense, assumed rate of return	30.00%
Non-U.S. Plans | Fixed income securities | Pension Plan
Defined Benefit Plan Disclosure
Assumptions for pension expense, assumed rate of return	70.00%