Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 29, 2019	Dec. 30, 2018	Sep. 30, 2018
Debt Instrument [Line Items]
Long-term debt, carrying cost	$ 1,709,895	$ 1,709,895	$ 1,709,895
Less: Deferred debt expenses	13,691	14,803	15,174
Long-term Debt, Excluding Current Maturities	1,696,204	1,695,092	1,694,721
Fair Value	1,845,985	1,685,936	1,720,608
6.35% Notes Due 2040
Debt Instrument [Line Items]
Long-term debt, carrying cost	500,000	500,000	500,000
Fair Value	$ 587,850	535,000	546,450
Interest Rate	6.35%
3.50% Notes Due 2027
Debt Instrument [Line Items]
Long-term debt, carrying cost	$ 500,000	500,000	500,000
Fair Value	$ 511,200	457,350	466,350
Interest Rate	3.50%
5.10% Notes Due 2044
Debt Instrument [Line Items]
Long-term debt, carrying cost	$ 300,000	300,000	300,000
Fair Value	$ 310,080	272,640	285,390
Interest Rate	5.10%
3.15% Notes Due 2021
Debt Instrument [Line Items]
Long-term debt, carrying cost	$ 300,000	300,000	300,000
Fair Value	$ 303,300	297,600	297,720
Interest Rate	3.15%
6.60% Debentures Due 2028
Debt Instrument [Line Items]
Long-term debt, carrying cost	$ 109,895	109,895	109,895
Fair Value	$ 133,555	$ 123,346	$ 124,698
Interest Rate	6.60%