Note 5 - Stock-based Compensation - Option Activity (Details) - USD ($)	12 Months Ended
	Feb. 26, 2023	Feb. 27, 2022	Feb. 28, 2021	Mar. 01, 2020
Outstanding options (in shares)	648,300	634,534	510,634
Balance, weighted average exercise price (in dollars per share)	$ 12.96	$ 12.47	$ 12.45
Outstanding aggregate intrinsic value	$ 2,159,000,000	$ 428,000,000	$ 730,000,000	$ 597,000,000
Outstanding options, granted (in shares)	134,100	147,750	132,100
Granted, weighted average exercise price (in dollars per share)	$ 12.08	$ 13.82	$ 12.55
Stock options exercised (in shares)	(13,000)	(75,334)	(1,450)
Exercised, weighted average exercise price (in dollars per share)	$ 10.67	$ 9.81	$ 8.02
Outstanding options, terminated or expired (in shares)	(98,975)	(58,650)	(6,750)
Terminated or expired, weighted average exercise price (in dollars per share)	$ 13.13	$ 13.96	$ 13.01
Outstanding options (in shares)	670,425	648,300	634,534
Balance, weighted average exercise price (in dollars per share)	$ 12.80	$ 12.96	$ 12.47
Balance, weighted average remaining contractual term (Year)	5 years 9 months 18 days
Vested and exercisable (in shares)	376,613
Vested and exercisable, weighted average exercise price (in dollars per share)	$ 12.67
Vested and exercisable, weighted average remaining contractual term (Year)	3 years 10 months 13 days
Vested and exercisable, aggregate intrinsic value	$ 1,262,000,000
Expected to vest (in shares)	640,256
Expected to vest, weighted average exercise price (in dollars per share)	$ 12.67
Expected to vest, weighted average remaining contractual term (Year)	5 years 9 months 18 days
Expected to vest, aggregate intrinsic value	$ 2,145