CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 26, 2021	Mar. 27, 2021	Jun. 27, 2020	Mar. 28, 2020	Jun. 26, 2021	Jun. 27, 2020
Statement of Comprehensive Income [Abstract]
Net earnings	$ 1,009,404		$ 1,367,055		$ 2,504,497	$ 2,034,390
Other Comprehensive Earnings [Abstract]
Unrealized gain (loss) on debt securities net of income taxes in 2021 and 2020, respectively.	12,977		260,078		(90,571)	122,495
Reclassification adjustment for net realized gain on debt securities net of income taxes in 2021 and 2020, respectively.	(3,333)		(2,195)		(8,916)	(3,921)
Adjustment to postretirement benefit obligation in 2021 and 2020, respectively.	1,380		814		2,759	1,629
Comprehensive earnings	$ 1,020,428	$ 1,387,341	$ 1,625,752	$ 528,841	$ 2,407,769	$ 2,154,593