Shareholders' Equity (Deficit): Stock Option Plans and Stock-Based Compensation (Details) - Stock options - USD ($)	6 Months Ended		12 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Dec. 29, 2018	Feb. 20, 2011
Number of Shares
Outstanding at the beginning of the period (in shares)	639,380
Granted (in shares)	29,250
Exercised (in shares)	(23,653)
Outstanding at the end of the period (in shares)	644,977		639,380
Exercisable at the end of the period (in shares)	482,452
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 84.12
Granted (in dollars per share)	164.84
Exercised (in dollars per share)	39.97
Outstanding at the end of the period (in dollars per share)	89.40		$ 84.12
Exercisable at the end of the period (in dollars per share)	$ 72.55
Weighted Average Remaining Contractual Life (years)
Outstanding	5 years 5 months 9 days		5 years 7 months 10 days
Exercisable at the end of the period	4 years 4 months 17 days
Intrinsic Value
Outstanding	$ 54,018,600		$ 47,808,100
Exercisable at the end of the period	$ 48,533,600
Weighted average assumptions and results used in estimation of fair value of options granted
Risk free interest rate (as a percent)	1.98%	2.73%
Expected life (years)	6 years	6 years
Expected volatility (as a percent)	20.30%	20.40%
Dividend yield (as a percent)	1.26%	1.17%
Option fair value (in dollars per share)	$ 32.65	$ 31.44
Additional disclosures
Compensation expense	$ 1,015,600	$ 1,006,900
Total unrecognized compensation expense	$ 4,300,000
Weighted average period for recognition of unrecognized compensation expense	2 years 7 months 6 days
2001 Plan
Stock Option Plans
Number of shares authorized for issuance				750,000
2010 Plan
Stock Option Plans
Number of shares authorized for issuance	700,000
Nonemployee Directors Plan
Stock Option Plans
Number of shares authorized for issuance	350,000