Note 7 - Debt (Details) (USD $) In Millions, unless otherwise specified				1 Months Ended			1 Months Ended	6 Months Ended	1 Months Ended	6 Months Ended
	Jun. 30, 2013	Jan. 29, 2013	Dec. 31, 2012	Jan. 29, 2013 Federal Funds Rate [Member] Base Rate Loans [Member]	Jan. 29, 2013 LIBOR [Member] Base Rate Loans [Member]	Jun. 30, 2013 LIBOR [Member]	Jan. 29, 2013 Minimum [Member]	Jun. 30, 2013 Minimum [Member]	Jan. 29, 2013 Maximum [Member]	Jun. 30, 2013 Maximum [Member]
Note 7 - Debt (Details) [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity (in Dollars)	$ 85.0	$ 95.0
Debt Instrument, Fee Amount (in Dollars)		0.3
Debt Instrument, Basis Spread on Variable Rate				0.50%	1.00%		0.50%		1.25%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage								1.50%		2.25%
Line of Credit Facility, Amount Outstanding (in Dollars)	12.6
Letters of Credit Outstanding, Amount (in Dollars)	39.2		39.6
Line of Credit Facility, Remaining Borrowing Capacity (in Dollars)	40.8
Line of Credit Facility, Interest Rate at Period End	5.00%					2.30%
Debt, Secured with a Cross Default Feature (in Dollars)	$ 134.9