Note 5 - Stock-based Compensation - Fair Value Assumptions (Details) - $ / shares	12 Months Ended
	Feb. 25, 2018	Feb. 26, 2017	Feb. 28, 2016
Weighted average fair value per share of option grants (in dollars per share)		$ 3.15	$ 5.30
Risk-free interest rates		1.77%
Expected stock price volatility		28.90%
Expected dividend yields		2.23%
Estimated option terms (in years) (Year)		5 years 109 days
Minimum [Member]
Risk-free interest rates			1.57%
Expected stock price volatility			27.91%
Expected dividend yields			1.84%
Estimated option terms (in years) (Year)			5 years 109 days
Maximum [Member]
Risk-free interest rates			1.86%
Expected stock price volatility			31.71%
Expected dividend yields			2.76%
Estimated option terms (in years) (Year)			7 years 328 days