Retirement Benefit Plans (Details 1) - USD ($)	3 Months Ended
	Apr. 03, 2021	Mar. 28, 2020
Total contributions for the period	$ 793,412	$ 854,776
Regular Matching Contributions [Member]
Total contributions for the period	191,808	204,992
Transitional Credit Contributions [Member]
Total contributions for the period	66,929	82,127
Non-Discretionary Contributions [Member]
Total contributions for the period	$ 534,675	$ 567,657