Shareholders' Equity (Deficit): (Tables)

12 Months Ended

Dec. 26, 2020

Shareholders' Equity (Deficit):

Schedule of stock option activity

				Weighted Average
				Remaining
	Number of	Weighted Average		Contractual Life
	Shares	Exercise Price		(years)	Intrinsic Value
Outstanding, December 30, 2017	658,184	$	72.33	5.87	$	37,723,800
Granted	69,000		149.51
Exercised	(79,241)		39.37
Forfeited	(8,563)		119.24
Outstanding, December 29, 2018	639,380		84.12	5.61		47,808,100
Granted	54,800		170.14
Exercised	(190,172)		57.41
Forfeited	(24,450)		138.13
Outstanding, December 28, 2019	479,558		101.78	5.79		45,283,200
Granted	45,100		163.87
Exercised	(108,170)		76.29
Forfeited	(23,000)		148.16
Outstanding, December 26, 2020	393,488	$	113.19	5.61	$	27,864,900
Exercisable, December 26, 2020	280,908	$	94.80	4.39	$	25,059,600

Schedule of weighted average assumptions used in estimation of fair value of options granted

	Year Ended
	December 26, 2020			December 28, 2019			December 29, 2018
Risk free interest rate		0.45	%		1.85	%		2.73	%
Expected life (years)		6			6			6
Expected volatility		25.03	%		19.30	%		19.94	%
Dividend yield		2.33	%		1.38	%		1.13	%
Option fair value	$	28.25		$	30.96		$	32.45