Shareholders' Equity (Deficit): Stock Option Plans and Stock-Based Compensation (Details) - Stock options - USD ($)	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Dec. 30, 2017	Feb. 20, 2011
Number of Shares
Outstanding at the beginning of the period (in shares)	658,184
Granted (in shares)	35,000
Exercised (in shares)	(27,697)
Forfeited (in shares)	(4,063)
Outstanding at the end of the period (in shares)	661,424		658,184
Exercisable at the end of the period (in shares)	487,335
Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 72.33
Granted (in dollars per share)	143.20
Exercised (in dollars per share)	41.39
Forfeited (in dollars per share)	113.95
Outstanding at the end of the period (in dollars per share)	77.12		$ 72.33
Exercisable at the end of the period (in dollars per share)	$ 62.07
Weighted Average Remaining Contractual Life (years)
Outstanding	5 years 8 months 9 days		5 years 10 months 13 days
Exercisable at the end of the period	4 years 7 months 28 days
Intrinsic Value
Outstanding	$ 47,178,100		$ 37,723,800
Exercisable at the end of the period	$ 42,095,400
Weighted average assumptions and results used in estimation of fair value of options granted
Risk free interest rate (as a percent)	2.73%	1.90%
Expected life (years)	6 years	6 years
Expected volatility (as a percent)	20.40%	26.93%
Dividend yield (as a percent)	1.17%	1.14%
Option fair value (in dollars per share)	$ 31.44	$ 31.38
Additional disclosures
Shares of previously owned common stock surrendered as payment for option shares exercised	2,249
Compensation expense	$ 1,006,900	$ 966,600
Total unrecognized compensation expense	$ 4,400,000
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