Earnings Per Share: (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 24, 2022	Sep. 25, 2021	Sep. 24, 2022	Sep. 25, 2021
Earnings Per Share:
Denominator for basic EPS - weighted average common shares	3,439,417	3,635,055	3,500,411	3,688,419
Dilutive shares associated with option plans	101,362	147,818	105,034	140,903
Denominator for diluted EPS - weighted average common shares and dilutive potential common shares	3,540,779	3,782,873	3,605,445	3,829,322
Options excluded from EPS calculation - anti-dilutive (in shares)	15,724	3,038	16,103	6,833