Note 5 - Stock-based Compensation - Fair Value Assumptions (Details) - $ / shares	12 Months Ended
	Feb. 26, 2023	Feb. 27, 2022	Feb. 28, 2021
Weighted average fair value per share of option grants (in dollars per share)	$ 2.66	$ 2.76	$ 2.12
Minimum [Member]
Risk-free interest rates	2.69%	0.74%	0.23%
Expected stock price volatility	27.90%	27.80%	26.90%
Expected dividend yields	3.17%	2.73%	3.18%
Estimated option terms (in years) (Year)	5 years 4 months 24 days	4 years 4 months 24 days	4 years 3 months 18 days
Maximum [Member]
Risk-free interest rates	3.64%	1.85%	0.42%
Expected stock price volatility	28.30%	29.20%	30.00%
Expected dividend yields	3.32%	3.07%	3.49%
Estimated option terms (in years) (Year)	8 years 1 month 6 days	7 years 7 months 6 days	7 years 7 months 6 days