Note 10 - $75,000,000 Revolving Credit Facility (Detail) (USD $)	6 Months Ended
	Jun. 30, 2012
Line of Credit Facility, Maximum Borrowing Capacity (in Dollars)	$ 75,000,000
Line of Credit Facility, Interest Rate Description	Borrowings bear interest at either, (i) the Eurodollar rate plus 0.70% or (ii) the prime rate.Letter of credit fees are equal to 0.70% times the maximum amount available to be drawn under outstanding letters of credit.
Line of Credit Facility, Commitment Fee Description	fifteen
Eurodollar Rate [Member]
Debt Instrument, Basis Spread on Variable Rate	0.70%
Letter of Credit [Member]
Debt Instrument, Basis Spread on Variable Rate	0.70%
Letter of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity (in Dollars)	$ 5,000,000