Note 6 - Debt (Details) (USD $)			9 Months Ended	1 Months Ended				1 Months Ended
	Sep. 27, 2014	Dec. 28, 2013	Sep. 27, 2014 Unsecured Revolving Credit Facility [Member] Base Rate [Member] J.P. Morgan Securities LLC [Member]	Jan. 30, 2014 Unsecured Revolving Credit Facility [Member] J.P. Morgan Securities LLC [Member]	Sep. 27, 2014 Unsecured Revolving Credit Facility [Member] J.P. Morgan Securities LLC [Member]	Jan. 29, 2014 Unsecured Revolving Credit Facility [Member] J.P. Morgan Securities LLC [Member]	May 31, 2013 Unsecured Revolving Credit Facility [Member] J.P. Morgan Securities LLC [Member]	May 31, 2013 J.P. Morgan Securities LLC [Member]
Note 6 - Debt (Details) [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				$ 275,000,000		$ 225,000,000	$ 225,000,000	$ 325,000,000
Loans Payable to Bank	95,000,000	98,750,000						100,000,000
Line of Credit Facility, Expiration Period								5 years
Line of Credit Facility, Increase in Maximum Borrowing Capacity				50,000,000
Debt Issuance Cost				100,000
Line of Credit Facility, Remaining Borrowing Capacity					$ 92,900,000
Debt Instrument, Basis Spread on Variable Rate			1.50%
Line of Credit Facility, Interest Rate at Period End					1.65%