Note 6 - Stockholders' Equity (Details Textual) - USD ($)	12 Months Ended
	May 28, 2017	May 29, 2016	May 31, 2015		May 29, 2017	May 25, 2014	Jul. 14, 2010
Common Stock, Voting Rights	1
Preferred Stock, Shares Authorized	2,000,000
Common Stock, Capital Shares Reserved for Future Issuance	2,200,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	155,239	465,968	881,143			2,000,000
Shares Paid for Tax Withholding for Share Based Compensation	137,089	95,550	112,443
Payments Related to Tax Withholding for Share-based Compensation	$ 434,000	$ 0	$ 343,000	[1]
Share-based Compensation Arrangement by Share-based Payment Award, Options Vested, Outstanding Number	1,021,097	963,833
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares	550,445	767,641
Issuance of common stock, per share (in dollars per share)	$ 13.65
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options	314,091
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 2,800,000
Stock Repurchase Program, Authorized Amount							$ 10,000,000
Preferred Stock, Shares Outstanding	0
Treasury Stock, Shares, Acquired	0	0	0
Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	30,000
Employee Stock Option [Member]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 4,600,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	1 year 182 days
Restricted Stock Units (RSUs) [Member]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	1 year 146 days
Stock Incentive Plan 2013 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant					2,000,000
Share--based Compensation Arrangement by Share-based Payment Award Options and Non Option Equity Instruments Outstanding Number	1,736,729
Stock Incentive Plan 2013 [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares Per Employee	500,000
Stock Incentive Plan 2013 [Member] | Stock Grants and Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares Per Employee	250,000
Stock Incentive Plan 2013 [Member] | Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares Per Employee	500,000
Stock Incentive Plan 2009 [Member]
Share--based Compensation Arrangement by Share-based Payment Award Options and Non Option Equity Instruments Outstanding Number		344,168
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		1,900,000

[1] See Note 1 - Organization, Basis of Presentation, and Summary of Significant Accounting Policies for a discussion of accounting principles adopted during the period.