Recent Accounting Pronouncements: (Details) - USD ($)	3 Months Ended
	Apr. 01, 2017	Mar. 26, 2016
Recently Adopted Accounting Pronouncements
Excess tax benefits on exercised stock options, operating activities	$ 96,100	$ 9,700
Accounting Standards Update 2016-09
Recently Adopted Accounting Pronouncements
Excess tax benefits on exercised stock options, operating activities	$ 96,100	9,700
Accounting Standards Update 2016-09 | Previously Reported
Recently Adopted Accounting Pronouncements
Excess tax benefits on exercised stock options, financing activities		$ 9,700