Note 6 - Stockholder's Equity (Details) - Valuation Assumptions, Stock Purchase Rights	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Note 6 - Stockholder's Equity (Details) - Valuation Assumptions, Stock Purchase Rights [Line Items]
Risk-free interest rate		0.30%
Employee Stock Purchase Plan [Member]
Note 6 - Stockholder's Equity (Details) - Valuation Assumptions, Stock Purchase Rights [Line Items]
Expected term (years)	6 months	6 months	6 months
Expected volatility	28.00%	45.80%	39.20%
Risk-free interest rate	0.10%	0.10%	0.10%