Shareholders' Equity (Deficit): Stock Options Activity (Details) - Stock options - USD ($)	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Number of Shares
Outstanding at the beginning of the period (in shares)	639,380	658,184	673,670
Granted (in shares)	54,800	69,000	69,500
Exercised (in shares)	(190,172)	(79,241)	(80,236)
Forfeited (in shares)	(24,450)	(8,563)	(4,750)
Outstanding at the end of the period (in shares)	479,558	639,380	658,184	673,670
Exercisable at the end of the period (in shares)	344,108
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 84.12	$ 72.33	$ 62.11
Granted (in dollars per share)	170.14	149.51	128.00
Exercised (in dollars per share)	57.41	39.37	33.41
Forfeited (in dollars per share)	138.13	119.24	95.28
Outstanding at the end of the period (in dollars per share)	101.78	$ 84.12	$ 72.33	$ 62.11
Exercisable at the end of the period (in dollars per share)	$ 83.08
Weighted Average Remaining Contractual Life (years)
Outstanding	5 years 9 months 15 days	5 years 7 months 10 days	5 years 10 months 13 days	6 years 1 month 10 days
Exercisable at the end of the period	4 years 8 months 9 days
Intrinsic Value
Outstanding at the beginning of the period	$ 47,808,100	$ 37,723,800	$ 43,139,100
Outstanding at the end of the period	45,283,200	$ 47,808,100	$ 37,723,800	$ 43,139,100
Exercisable at the end of the period	$ 38,930,300
Weighted average assumptions and results used in estimation of fair value of options granted
Risk free interest rate (as a percent)	1.85%	2.73%	2.05%
Expected life (years)	6 years	6 years	6 years
Expected volatility (as a percent)	19.30%	19.94%	25.64%
Dividend yield (as a percent)	1.38%	1.13%	1.10%
Option fair value (in dollars per share)	$ 30.96	$ 32.45	$ 32.07