CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) (Parenthetical) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Other comprehensive income/(loss):
Change in fair value of marketable securities, tax benefit/(cost)	$ 3,008	$ 0	$ (463)	$ 0
Change in fair value of interest rate swap and marketable securities, tax benefit/(cost)	45,197	19,202	69,817	59,166
Change in pension and postretirement benefit costs, tax expense	$ 70,938	$ 65,843	$ 141,876	$ 131,685