Shareholders' Equity (Deficit): Additional Information (Details) - Stock options - USD ($)	12 Months Ended
	Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Additional disclosures
Total intrinsic value of options exercised	$ 8,400,000	$ 22,700,000	$ 8,300,000
Total fair value of shares vested	$ 9,100,000	$ 8,600,000	$ 7,800,000
Shares of previously owned common stock surrendered as payment for option shares exercised	0	0	2,249
Compensation expense	$ 1,315,200	$ 1,666,400	$ 1,976,100
Total unrecognized compensation expense	$ 3,700,000
Weighted average period for recognition of unrecognized compensation expense	2 years 7 months 6 days