Shareholders' Equity (Deficit): Additional Information (Details) - Stock options - USD ($)	12 Months Ended
	Dec. 25, 2021	Dec. 26, 2020	Dec. 28, 2019
Additional disclosures
Total intrinsic value of options exercised	$ 16,200,000	$ 8,400,000	$ 22,700,000
Total fair value of shares vested	9,000,000.0	9,100,000	8,600,000
Compensation expense	1,435,500	$ 1,315,200	$ 1,666,400
Total unrecognized compensation expense	$ 4,000,000.0
Weighted average period for recognition of unrecognized compensation expense	2 years 10 months 24 days