Shareholders' Equity (Deficit): Stock Options Activity (Details) - Stock options - USD ($)	12 Months Ended
	Dec. 25, 2021	Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Number of Shares
Outstanding at the beginning of the period (in shares)	393,488	479,558	639,380
Granted (in shares)	72,600	45,100	54,800
Exercised (in shares)	(105,617)	(108,170)	(190,172)
Forfeited (in shares)	(4,850)	(23,000)	(24,450)
Outstanding at the end of the period (in shares)	355,621	393,488	479,558	639,380
Exercisable at the end of the period (in shares)	219,266
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 113.19	$ 101.78	$ 84.12
Granted (in dollars per share)	226.96	163.87	170.14
Exercised (in dollars per share)	78.78	76.29	57.41
Forfeited (in dollars per share)	158.48	148.16	138.13
Outstanding at the end of the period (in dollars per share)	146.03	$ 113.19	$ 101.78	$ 84.12
Exercisable at the end of the period (in dollars per share)	$ 114.16
Weighted Average Remaining Contractual Life (years)
Outstanding	6 years 3 months 25 days	5 years 7 months 9 days	5 years 9 months 14 days	5 years 7 months 9 days
Exercisable at the end of the period	4 years 8 months 23 days
Intrinsic Value
Outstanding at the beginning of the period	$ 27,864,900	$ 45,283,200	$ 47,808,100
Outstanding at the end of the period	39,320,571	$ 27,864,900	$ 45,283,200	$ 47,808,100
Exercisable at the end of the period	$ 28,004,239
Weighted average assumptions and results used in estimation of fair value of options granted
Risk free interest rate (as a percent)	1.13%	0.45%	1.85%
Expected life (years)	6 years	6 years	6 years
Expected volatility (as a percent)	25.51%	25.03%	19.30%
Dividend yield (as a percent)	3.13%	2.33%	1.38%
Option fair value (in dollars per share)	$ 37.90	$ 28.25	$ 30.96