Note 5 - Stockholders' Equity - Stock-based Compensation Activity (Details) - $ / shares	12 Months Ended
	May 29, 2016	May 31, 2015	May 25, 2014
Restricted Stock [Member]
Balance (in shares)	392,771	149,300	95,330
Balance (in dollars per share)	$ 14.15	$ 13.17	$ 6.52
Granted (in shares)	177,675	324,357	128,631
Granted (in dollars per share)	$ 12.10	$ 13.97	$ 14.30
Awarded/Exercised (in shares)	(32,439)	(79,219)	(62,499)
Awarded/Exercised (in dollars per share)	$ 13.28	$ 11.57	$ 6.18
Forfeited (in shares)	(11,166)	(1,667)	(12,162)
Forfeited (in dollars per share)	$ 14.36	$ 14.30	$ 8.86
Balance (in shares)	526,841	392,771	149,300
Balance (in dollars per share)	$ 13.51	$ 14.15	$ 13.17
Awarded/Exercised (in dollars per share)	13.28	11.57	6.18
Forfeited (in dollars per share)	14.36	14.30	8.86
Granted (in dollars per share)	$ 12.10	$ 13.97	$ 14.30
Employee Stock Option [Member]
Balance (in shares)	1,736,718	1,215,860	1,339,892
Balance (in dollars per share)	$ 11.19	$ 8.45	$ 6.58
Granted (in shares)	265,500	794,500	291,500
Granted (in dollars per share)	$ 12.04	$ 14.20	$ 14.30
Awarded/Exercised (in shares)	(220,717)	(205,419)	(398,080)
Awarded/Exercised (in dollars per share)	$ 6.44	$ 6.55	$ 6.45
Forfeited (in shares)	(24,473)	(2,223)	(12,452)
Forfeited (in dollars per share)	$ 14.38	$ 14.30	$ 6.66
Plan shares expired (in shares)	(25,554)	(66,000)	(5,000)
Plan shares expired (in dollars per share)	$ 9.86	$ 11.32	$ 13.32
Balance (in shares)	1,731,474	1,736,718	1,215,860
Balance (in dollars per share)	$ 11.90	$ 11.19	$ 8.45
Balance (in shares)	881,143	2,000,000	422,977
Balance (in dollars per share)	$ 14.02	$ 14.15
Additional shares reserved (in shares)			2,000,000
Granted (in shares)	(443,175)	(1,118,857)	(420,131)
Plan shares expired (in shares)			(2,846)
Balance (in shares)	465,968	881,143	2,000,000
Balance (in dollars per share)		$ 14.02	$ 14.15
Forfeited (in shares)	28,000