CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Statement of Comprehensive Income [Abstract]
Net earnings	$ 616,172	$ 495,072	$ 1,296,443	$ 1,050,343
Other comprehensive earnings:
Unrealized (loss) on debt securities net of income taxes of in 2018. Unrealized gain on debt and equity securities net of income taxes in 2017.	(2,600)	23,624	(26,581)	62,542
Reclassification adjustment for net realized loss on debt securities net of income taxes in 2018. Reclassification adjustment for net realized (gain) on debt and equity securities net of income taxes in 2017.	425	(38,834)	447	(58,021)
Adjustment to postretirement benefit obligation net of income taxes in 2018.	564	0	1,129	0
Comprehensive earnings	$ 614,561	$ 479,862	$ 1,271,438	$ 1,054,864